Noncoding RNAs in gastric cancer: implications for drug resistance

DHRS4-AS1 regulate gastric cancer apoptosis and cell proliferation by destabilizing DHX9 and inhibited the association between DHX9 and ILF3

Gastric cancer (GC) causes millions of cancer-related deaths due to anti-apoptosis and rapid proliferation. However, the molecular mechanisms underlying GC cell proliferation and anti-apoptosis remain unclear. The expression levels of DHRS4-AS1 in GC were analyzed based on GEO database and recruited GC patients in our institution. We found that DHRS4-AS1 was significantly downregulated in GC. The expression of DHRS4-AS1 in GC tissues showed a significant correlation with tumor size, advanced pathological stage, and vascular invasion. Moreover, DHRS4-AS1 levels in GC tissues were significantly associated with prognosis. DHRS4-AS1 markedly inhibited GC cell proliferation and promotes apoptosis in vitro and in vivo assays. Mechanically, We found that DHRS4-AS1 bound to pro-oncogenic DHX9 (DExH-box helicase 9) and recruit the E3 ligase MDM2 that contributed to DHX9 degradation. We also confirmed that DHRS4-AS1 inhibited DHX9-mediated cell proliferation and promotes apoptosis. Furthermore, we found DHX9 interact with ILF3 (Interleukin enhancer Binding Factor 3) and activate NF-kB Signaling in a ILF3-dependent Manner. Moreover, DHRS4-AS1 can also inhibit the association between DHX9 and ILF3 thereby interfered the activation of the signaling pathway. Our results reveal new insights into mechanisms underlying GC progression and indicate that LncRNA DHRS4-AS1 could be a future therapeutic target and a biomarker for GC diagnosis.

Long noncoding RNA NONHSAT160169.1 promotes resistance via hsa-let-7c-3p/SOX2 axis in gastric cancer

In clinical trials involving patients with HER2 (ERBB2 receptor tyrosine kinase 2) positive gastric cancer, the efficacy of the HER2-targeted drug lapatinib has proven to be disappointingly poor. Under the persistent pressure exerted by targeted drug therapy, a subset of tumor cells exhibit acquired drug resistance through the activation of novel survival signaling cascades, alongside the proliferation of tumor cells that previously harbored mutations conferring resistance to the drug. This study was undertaken with the aim of elucidating in comprehensive detail the intricate mechanisms behind adaptive resistance and identifying novel therapeutic targets that hold promise in the development of effective lapatinib-based therapies for the specific subset of patients afflicted with gastric cancer. We have successfully established a gastric cancer cell line with acquired lapatinib resistance, designated as HGC-27-LR cells. Utilizing comprehensive coding and noncoding transcriptome sequencing analysis, we have identified key factors that regulate lapatinib resistance in HGC-27 cells. We have compellingly validated that among all the lncRNAs identified in HGC-27-LR cells, a novel lncRNA (long noncoding RNA) named NONHSAT160169.1 was found to be most notably upregulated following exposure to lapatinib treatment. The upregulation of NONHSAT160169.1 significantly augmented the migratory, invasive, and stemness capabilities of HGC-27-LR cells. Furthermore, we have delved into the mechanism by which NONHSAT160169.1 regulates lapatinib resistance. The findings have revealed that NONHSAT160169.1, which is induced by the p-STAT3 (signal transducer and activator of transcription 3) nuclear transport pathway, functions as a decoy that competitively interacts with hsa-let-7c-3p and thereby abrogates the inhibitory effect of hsa-let-7c-3p on SOX2 (SRY-box transcription factor 2) expression. Hence, our study has unveiled the NONHSAT160169.1/hsa-let-7c-3p/SOX2 signaling pathway as a novel and pivotal axis for comprehending and surmounting lapatinib resistance in the treatment of HER2-positive gastric cancer.

Application of CD34 expression combined with three-phase dynamic contrast-enhanced computed tomography scanning in preoperative staging of gastric cancer

BACKGROUND

Accurate preoperative staging of gastric cancer (GC), a common malignant tumor worldwide, is critical for appropriate treatment plans and prognosis. Dynamic three-phase enhanced computed tomography (CT) scanning for preoperative staging of GC has limitations in evaluating tumor angiogenesis. CD34, a marker on vascular endothelial cell surfaces, is promising in evaluating tumor angiogenesis. We explored the value of their combination for preoperative staging of GC to improve the efficacy and prognosis of patients with GC.

AIM

To explore the evaluation value of CD34 expression + dynamic three-phase enhanced CT scanning in preoperative staging of GC.

METHODS

Medical records of 106 patients with GC treated at the First People's Hospital of Lianyungang between February 2021 and January 2023 were retrospectively studied. All patients underwent three-phase dynamic contrast-enhanced CT scanning before surgery, and CD34 was detected in gastroscopic biopsy specimens. Using surgical and pathological results as the gold standard, the diagnostic results of three-phase dynamic contrast-enhanced CT scanning at different T and N stages were analyzed, and the expression of CD34-marked microvessel density (MVD) at different T and N stages was determined. The specificity and sensitivity of three-phase dynamic contrast-enhanced CT and CD34 in T and N staging were calculated; those of the combined diagnosis of the two were evaluated in parallel. Independent factors affecting lymph node metastasis were analyzed using multiple logistic regression.

RESULTS

The accuracy of three-phase dynamic contrast-enhanced CT scanning in diagnosing stages T1, T2, T3 and T4 were 68.00%, 75.00%, 79.41%, and 73.68%, respectively, and for diagnosing stages N0, N1, N2, and N3 were 75.68%, 74.07%, 85.00%, and 77.27%, respectively. CD34-marked MVD expression increased with increasing T and N stages. Specificity and sensitivity of three-phase dynamic contrast-enhanced CT in T staging were 86.79% and 88.68%; for N staging, 89.06% and 92.86%; for CD34 in T staging, 64.15% and 88.68%; and for CD34 in N staging, 84.38% and 78.57%, respectively. Specificity and sensitivity of joint diagnosis in T staging were 55.68% and 98.72%, and N staging were 75.15% and 98.47%, respectively, with the area under the curve for diagnosis improving accordingly. According to multivariate analysis, a longer tumor diameter, higher pathological T stage, lower differentiation degree, and higher expression of CD34-marked MVD were independent risk factors for lymph node metastasis in patients with GC.

CONCLUSION

With high accuracy in preoperatively determining the invasion depth and lymph node metastasis of GC, CD34 expression and three-phase dynamic contrast-enhanced CT can provide a reliable basis for surgical resection.

Research progress of ginger in the treatment of gastrointestinal tumors

Cancer seriously endangers human health. Gastrointestinal cancer is the most common and major malignant tumor, and its morbidity and mortality are gradually increasing. Although there are effective treatments such as radiotherapy and chemotherapy for gastrointestinal tumors, they are often accompanied by serious side effects. According to the traditional Chinese medicine and food homology theory, many materials are both food and medicine. Moreover, food is just as capable of preventing and treating diseases as medicine. Medicine and food homologous herbs not only have excellent pharmacological effects and activities but also have few side effects. As a typical medicinal herb with both medicinal and edible uses, some components of ginger have been shown to have good efficacy and safety against cancer. A mass of evidence has also shown that ginger has anti-tumor effects on digestive tract cancers (such as gastric cancer, colorectal cancer, liver cancer, laryngeal cancer, and pancreatic cancer) through a variety of pathways. The aim of this study is to investigate the mechanisms of action of the main components of ginger and their potential clinical applications in treating gastrointestinal tumors.

LncRNA POU6F2-AS2 contributes to malignant phenotypes and paclitaxel resistance by promoting SKP2 expression in stomach adenocarcinoma

This study aimed to investigate the role and mechanism of POU6F2-AS2 in the development of gastric cancer. POU6F2-AS2 expression was considerably higher in clinical stomach adenocarcinoma (STAD) tissues and gastric cancer cell lines (MKN-28 and MGC-803) than in neighbouring normal tissues and gastric mucosa epithelial cells (GES-1). POU6F2-AS2 overexpression resulted in a low overall survival probability, progression-free survival probability and post progression survival probability, as well as increased cell viability, migration and invasion of gastric cancer cells, thereby inhibiting apoptosis. Based on RNA pull-down, cycloheximide and MG132 incubation experiments, POU6F2-AS2 promoted SKP2 by stabilizing NONO expression. In addition, in vivo silencing of POU6F2-AS2 in gastric cancer cells can inhibit tumour progression and produce a synergistic antitumour effect when combined with paclitaxel. POU6F2-AS2 is overexpressed in STAD, which is attributed to a bad prognosis. In vitro and in vivo experiments have confirmed that the POU6F2-AS2/NONO/SKP2 axis promotes STAD progression, and that the silencing of POU6F2-AS2 plays a synergistic antitumour effect when combined with paclitaxel. Therefore, POU6F2-AS2 may be potentially developed as a target to inhibit STAD and reduce chemoresistance.

Biomimetic Nanophotosensitizer Amplifies Immunogenic Pyroptosis and Triggers Synergistic Cancer Therapy

Immunotherapy is considered to be an effective treatment for cancer and has drawn extensive interest. Nevertheless, the insufficient antigenicity and immunosuppressive tumor microenvironment often cause unsatisfactory therapeutic efficacy. Herein, a photo-activated reactive oxygen species (ROS) amplifying system (defined as "M-Cu-T") is developed to induce antitumor immune response by triggering a tumor-specific immunogenic pyroptosis. In M-Cu-T, M1 macrophage membrane-based vesicles are used for drug loading and tumor targeting, photosensitizers (meso-tetra(4-aminophenyl) porphyrin, TAPP) are used as a pyroptosis inducer, copper ions (Cu2+ ) can enhance ROS-induced pyroptosis by consuming antioxidant systems in cells. As expected, the prepared M-Cu-T targets enrichment into tumor cells and cascades the generation of ROS, which further induces pyroptosis through caspase 3-mediated gasdermin E (GSDME) cleavage under laser activation. The pyroptotic cancer cells accompanying secrete related pattern molecules, induce immunogenic cell death, and activate antitumor immunity for immunotherapy. An effective tumor ablation is observed in LLC and CT26 cancer mouse models. This study provides inspiration for boosting the immunogenicity and achieving satisfactory therapeutic effects in cancer therapy.

Antitumor effect of luteolin proven by patient-derived organoids of gastric cancer

Luteolin (Lut) has been shown to inhibit gastric cancer (GC); however, its efficacy compared to other clinical drugs has not been examined in human samples. This study aimed to elucidate the antitumor activity of Lut in GC patient-derived organoids (PDOs). PDOs were established from GC cancer tissues, and the characterization of tissues and PDOs was performed using whole-exome sequencing. Drug sensitivity tests were performed by treating PDOs with Lut, norcantharidin (NCTD), and carboplatin (CP). RNA sequencing of PDOs was performed to elucidate the antitumor mechanism of Lut, which was further verified in three GC cell lines. Eleven PDOs were successfully constructed, and were highly consistent with the pathophysiology and genetic changes in the corresponding tumors. The IC50s of Lut, NCTD, and CP of PDOs were 27.19, 23.9, and 37.87 μM, respectively. Lut treatment upregulated FOXO3, DUSP1, and CDKN1A expression and downregulated IL1R1 and FGFR4 expression in GC cell lines, which was consistent with the results of PDOs. We demonstrate that Lut exerted stronger antitumor effects than CP, but a similar effect to that of NCTD, which was obtained in an in vitro PDO system. Additionally, Lut exerted varying degrees of antitumor effects against the PDOs, thereby indicating that PDO may be a useful preclinical drug screening tool for personalized treatment.

RP11-789C1.1 inhibits gastric cancer cell proliferation and accelerates apoptosis via the ATR/CHK1 signaling pathway

BACKGROUND

Long non-coding RNAs (lncRNAs) plays an important role in the progression of gastric cancer (GC). Their involvement ranges from genetic regulation to cancer progression. However, the mechanistic roles of RP11-789C1.1 in GC are not fully understood.

METHODS

We identified the expression of lncRNA RP11-789C1.1 in GC tissues and cell lines by real-time fluorescent quantitative polymerase chain reaction. A series of functional experiments revealed the effect of RP11-789C1.1 on the proliferation of GC cells. In vivo experiments verified the effect of RP11-789C1.1 on the biological behavior of a GC cell line. RNA pull-down unveiled RP11-789C1.1 interacting proteins. Western blot analysis indicated the downstream pathway changes of RP11-789C1.1, and an oxaliplatin dosing experiment disclosed the influence of RP11-789C1.1 on the drug sensitivity of oxaliplatin.

RESULTS

Our results demonstrated that RP11-789C1.1 inhibited the proliferation of GC cells and promoted the apoptosis of GC cells. Mechanistically, RP11-789C1.1 inhibited checkpoint kinase 1 (CHK1) phosphorylation by binding ataxia-telangiectasia mutated and Rad3 related (ATR), a serine/threonine-specific protein kinase, promoted GC apoptosis, and mediated oxaliplatin sensitivity.

CONCLUSION

In general, we discovered a tumor suppressor molecule RP11-789C1.1 and confirmed its mechanism of action, providing a theoretical basis for targeted GC therapy.

LncRNA-SNHG1 promotes paclitaxel resistance of gastric cancer cells through modulating the miR-216b-5p-hexokianse 2 axis

Gastric cancer (GC) is one of the most malignant tumors with high incidence and poor prognosis. Currently, the combination of surgery with chemo- or radiotherapy is widely applied therapeutic strategy against GC. However, development of drug resistance severely limited the clinical application of chemotherapy. Small nucleolar RNA host gene 1 (SNHG1) has been reported to be frequently overexpressed in diverse human tumors. Yet, the biological roles and mechanisms of SNHG1 in chemoresistant GC remain unclear. Expressions of lncRNA and miRNA were detected by qRT-PCR. Responses of GC cells to Taxol treatments were evaluated by cell viability assay and apoptosis assay. Glucose metabolism rate was examined by glucose uptake and extracellular acidification rate (ECAR). The lncRNA-miRNA interaction was validated by RNA pull-down assay and luciferase assays. This study reports that expressions of SNHG1 were significantly elevated in patients with GC and gastric cancer cell lines. Silencing SNHG1 effectively suppressed GC cells migration and increased the Taxol sensitivity of GC cells. Moreover, we detected remarkedly upregulated SNHG1 expression and increased glucose metabolism in Taxol resistant cell line, MKN-45 TXR. Low glucose supply rendered Taxol resistant cells more susceptible to Taxol treatment compared with that from MKN-45 parental cells. Bioinformatical analysis, RNA pull-down and luciferase assays verified that SNHG1 functioned as a ceRNA of miR-216b-5p in GC cells. Consistently, we detected miR-216b-5p was significantly downregulated in GC tumor specimens and Taxol resistant GC cells. The hexokinase 2 (HK2), a glucose metabolism key enzyme, was predicted and validated as a direct target of miR-216b-5p in GC cells. Finally, restoration of miR-216b-5p in SNHG1-overexpressing MKN-45 TXR cells successfully overrode the SNHG1-promoted Taxol resistance through targeting the HK2-glycolysis axis. This study uncovered new biological roles and molecular mechanisms of the lncRNA-SNHG1-mediated Taxol resistance of gastric cancer, suggesting targeting the SNHG1-miR-216b-5p-HK2 axis could be a potentially therapeutic approach against chemoresistant gastric cancer.

Unrevealing the vital role of ncRNAs in Gastric Cancer chemoresistance

The high incidence of gastric cancer in many nations and poor overall survival rates has remained a serious global health concern. Chemoresistance in gastric cancer is a significant issue that hinders the efficacy of available treatment options. In gastric cancer, non-coding RNAs like microRNAs, long non-coding RNAs, and circular RNAs have become effective regulators of chemoresistance. These non-coding RNAs can influence several mechanisms, including drug efflux transporters, drug metabolism, and detoxification, cancer stem cells and the epithelial-mesenchymal transition, autophagy and apoptosis, and the tumor microenvironment. In this article review, we summarize the key roles non-coding RNAs play in the chemoresistance of gastric cancer and consider how they might be used in clinical settings as markers for diagnosis and prognosis, as well as potential targets and treatment plans. We also emphasize the need for additional study and collaborations in this area and highlight the difficulties and opportunities in non-coding RNA research for gastric cancer chemoresistance. This review offers crucial insights into the intricate relationship between non-coding RNAs and chemoresistance in gastric cancer, with implications for precision oncology and personalized medicine.

Targeting HSP90 with picropodophyllin suppresses gastric cancer tumorigenesis by disrupting the association of HSP90 and AKT

Gastric cancer (GC) is one of the most common malignant tumors worldwide. Thus, the development of safe and effective therapeutic compounds for GC treatment is urgently required. Here, we aimed to examine the role of picropodophyllin (PPP), a compound extracted from the rhizome of Dysosma versipellis (Hance) M. Cheng ex Ying, on the proliferation of GC cells. Our study revealed that PPP inhibits the proliferation of GC cells in a dose-dependent manner by inducing apoptosis. Moreover, our study elucidated that PPP suppresses the growth of GC tumor xenografts with no side effects of observable toxicity. Mechanistically, PPP exerts its effects by blocking the AKT/mammalian target of rapamycin (mTOR) signaling pathway; these effects are markedly abrogated by the overexpression of constitutively active AKT. Furthermore, drug affinity responsive target stability (DARTS) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) revealed that heat shock protein 90 (HSP90) may be a potential target of PPP. Surface plasmon resonance and immunoprecipitation assay validated that PPP directly targets HSP90 and disrupts the binding of HSP90 to AKT, thereby suppressing GC cell proliferation. Thus, our study revealed that PPP may be a promising therapeutic compound for GC treatment.

H1Innovative approaches to combat anti-cancer drug resistance: Targeting lncRNA and autophagy

BACKGROUND

To date, standardizing clinical predictive biomarkers for assessing the response to immunotherapy remains challenging due to variations in personal genetic signatures, tumour microenvironment complexities and epigenetic onco-mechanisms.

MAIN BODY

Early monitoring of key non-coding RNA (ncRNA) biomarkers may help in predicting the clinical efficacy of cancer immunotherapy and come up with standard predictive ncRNA biomarkers. For instance, reduced miR-125b-5p level in the plasma of non-small cell lung cancer patients treated with anti-PD-1 predicts a positive outcome. The level of miR-153 in the plasma of colorectal cancer patients treated with chimeric antigen receptor T lymphocyte (CAR-T) cell therapy may indicate the activation of T-cell killing activity. miR-148a-3p and miR-375 levels may forecast favourable responses to CAR-T-cell therapy in B-cell acute lymphoblastic leukaemia. In cancer patients treated with the GPC3 peptide vaccine, serum levels of miR-1228-5p, miR-193a-5p and miR-375-3p were reported as predictive biomarkers of good response and improved overall survival. Therefore, there is a critical need for further studies to elaborate on the key ncRNA biomarkers that have the potential to predict early clinical responses to immunotherapy.

CONCLUSIONS

This review summarises important predictive ncRNA biomarkers that were reported in cancer patients treated with different immunotherapeutic modalities including monoclonal antibodies, small molecule inhibitors, cancer vaccines and CAR-T cells. In addition, a concise discussion on forthcoming perspectives is provided, outlining technical approaches for the optimal utilisation of immune-modulatory ncRNA biomarkers as predictive tools and therapeutic targets.

CircHIPK3 contributes to cisplatin resistance in gastric cancer by blocking autophagy-dependent ferroptosis

Cisplatin is the first-line chemotherapy for gastric cancer (GC). However, its efficacy is dampened by the development of chemoresistance, which leads to poor prognosis in GC patients. Recently, evidence has revealed that circular RNAs (circRNAs) and dysregulation of autophagy-dependent ferroptosis play critical roles in cancer chemoresistance. Herein, for the first time we report that circHIPK3 has a vital role in GC cisplatin resistance. CircHIPK3 regulated cisplatin resistance by targeting autophagy and ferroptosis. In brief, knockdown circHIPK3 decreased GC cell cisplatin resistance by enhancing ferroptosis via the miR-508-3p/Bcl-2/beclin1/SLC7A11 axis. Taken together, our results demonstrate that ferroptosis is a promising strategy to ameliorate cisplatin resistance. Importantly, serum exosomal circHIPK3 could also be a noninvasive indicator to evaluate cisplatin resistance in GC.

Serum basic fibroblast growth factor and interleukin-1β predict the effect of first-line chemotherapy in patients with advanced gastric cancer

BACKGROUND

The incidence and mortality rates of gastric cancer in China are the second-highest in the world, and most patients with gastric cancer lose their chance of surgery by the time of their diagnosis.

AIM

To explore the predictive potential of serum basic fibroblast growth factor and interleukin-1β levels for the effect of first-line chemotherapy in patients with advanced gastric cancer.

METHODS

From the gastric cancer patients admitted to our hospital from May 2019 to April 2023, 84 patients were selected and randomly and equally assigned to the experimental or control group. The FLOT group received the FLOT chemotherapy regimen (composed of oxaliplatin + calcium folinate + fluorouracil + paclitaxel), while the SOX group received the SOX chemotherapy regimen (composed of oxaliplatin + tiga capsules). The clinical efficacy, tumor marker levels, adverse reactions, and survival rates of the two groups were compared 7 days after the end of the relevant treatments.

RESULTS

The target effective rate of the FLOT group was 54.76%, which was much higher than that of the SOX group (33.33%; P < 0.05). After treatment, both the groups demonstrated lower levels of cancer antigen (CEA), carbohydrate antigen 199 (CA199), and peptide tissue antigen (TPS). For several patients before treatment (P < 0.05). Third and fourth grades. In terms of adverse reactions, the level of white blood cells in both the groups was lower. Moreover, the incidence of hand-foot skin reactions in these two study groups was lower (P < 0.05), while those of peripheral neuritis, vomiting, diarrhea, and abnormal liver function were significant (P < 0.05). No statistically significant difference was noted between the two groups (P < 0.05). The 1-year survival rate was higher in the FLOT group (P < 0.05).

CONCLUSION

The FLOT regimen was effective in reducing the serum CEA, CA199, and TPS levels as well as in improving the 1-year survival rate of patients with good tolerability, making it worthy of clinical promotion and application.

ELOA promotes tumor growth and metastasis by activating RBP1 in gastric cancer

BACKGROUND

Elongin A (ELOA), our previous work revealed, serves as a novel tumor suppressor in colorectal cancer. However, the function and mechanism of ELOA in other cancer types, including gastric cancer (GC), remain to be elucidated.

METHODS

The expression of ELOA was measured by quantitative reverse transcription-polymerase chain reaction and western blot. The effects of ELOA on GC growth and metastasis were assessed through a series of in-vitro and in-vivo assays. Furthermore, the potential mechanism of ELOA was revealed by RNA sequencing, dual luciferase reporter assay, chromatin immunoprecipitation, and rescue experiments in GC.

RESULTS

We uncovered increased expression of ELOA in GC tissues compared with paired normal tissues via bioinformatic analyses and our sample detection. Enhanced ELOA expression in GC tissues was obviously correlated with poor tumor differentiation, lymph node metastasis, advanced tumor stage, and a poor prognosis. A series of functional experiments showed that ELOA promoted the proliferation and metastasis of GC. Mechanistically, we revealed that the decreased levels of miR-490-3p caused the upregulation of ELOA in GC. Both RNA-seq and ChIP assays revealed that ELOA transcriptionally activated retinol-binding protein 1 (RBP1) by binding to its promotor. Furthermore, specific knockdown of RBP1 reduced the tumor-promoting ability of ELOA in GC cells.

CONCLUSIONS

In summary, our findings demonstrate that ELOA exerts oncogenic properties by activating RBP1 expression, providing the basis for a promising therapeutic target in GC.

Long non-coding RNA SOX21-AS1: A potential tumor oncogene in human cancers

Emerging data have proposed that the aberrant level of long noncoding RNAs (lncRNA) is related to the onset and progression of cancer. Among them, lncRNA SOX21-AS1 was shown to upregulate and seem to be a novel oncogene in various cancer, including ovarian cancer, lung cancer, breast cancer, pancreatic cancer, osteosarcoma, and melanoma. Available data indicated that SRY-box transcription factor 21 antisense divergent transcript 1 (SOX21-AS1) mostly acts as a competing endogenous RNA (ceRNA) to inhibit the level of its target microRNAs (miRNAs), leading to upregulation of their targets. In addition, SOX21-AS1 is engaged in various signaling pathways like transforming growth factor-β (TGF-β) signaling, Wnt signaling, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling. Moreover, this lncRNA was revealed to be correlated with the clinicopathological features of affected patients. SOX21-AS1 was also proved to enhance the resistance of ovarian cancer cells to cisplatin chemotherapy. SOX21-AS1 is markedly associated with poor prognosis and low survival of patients, proposing that it may be a prognostic and diagnostic biomarker in cancer. Overexpression of SOX21-AS1 is related to various cancer-related pathways, like epithelial mesenchymal transition (EMT), invasion, migration, apoptosis, and cell cycle arrest. In this work, we aimed to discuss the biogenesis, function, and underlying molecular mechanism of SOX21-AS1 in cancer progression as well as its potential as a prognostic and diagnostic biomarker in human cancers.

A novel copper-induced cell death-related lncRNA prognostic signature associated with immune infiltration and clinical value in gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most important malignancies and has a poor prognosis. Copper-induced cell death, recently termed cuproptosis, may directly affect the outcome of GC. Long noncoding RNAs (lncRNAs), possessing stable structures, can influence the prognosis of cancer and may serve as potential prognostic prediction factors for various cancers. However, the role of copper cell death-related lncRNAs (CRLs) in GC has not been thoroughly investigated. Here, we aim to elucidate the role of CRLs in predicting prognosis, diagnosis, and immunotherapy in GC patients.

METHODS

RNA expression data for 407 GC patients from The Cancer Genome Atlas (TCGA) were gathered, and differentially expressed CRLs were identified. Subsequently, the researchers applied univariate, LASSO, and multivariate Cox regression to construct a prognostic signature consisting of 5 lncRNAs based on the CRLs. Stratified by the median CRLSig risk score, Kaplan-Meier analysis was utilized to compare overall survival (OS) between the high- and low-risk groups. Among the two groups, gene set enrichment analysis (GSEA), tumor microenvironment (TME), drug sensitivity analysis, and immune checkpoint analysis were conducted. In addition, consensus clustering and nomogram analysis were performed to predict OS. Cell experiments and 112 human serum samples were employed to verify the effect of lncRNAs on GC. Furthermore, the diagnostic value of the CRLSig in the serum of GC patients was analyzed by the receiver operating characteristic (ROC) curve.

RESULTS

A prognostic signature for GC patients was constructed based on CRLs, composed of AC129926.1, AP002954.1, AC023511.1, LINC01537, and TMEM75. According to the K-M survival analysis, high-risk GC patients had a lower OS rate and progression-free survival rate than low-risk GC patients. Further support for the model's accuracy was provided by ROC, principal component analysis, and the validation set. The area under the curve (AUC) of 0.772 for GC patients showed a better prognostic value than any other clinicopathological variable. Furthermore, immune infiltration analysis showed that the high-risk group had greater antitumor immune responses in the tumor microenvironment. In the high-risk subgroup, 23 immune checkpoint genes had significantly higher expression levels than in the low-risk subgroup (p < 0.05). The half-maximal inhibitory concentrations (IC50) of 86 drugs were found to be significantly different in the two groups. Accordingly, the model is capable of predicting the effectiveness of immunotherapy. In addition, the five CRLs in GC serum exhibited statistically significant expression levels. The AUC of this signature in GC serum was 0.894, with a 95% CI of 0.822-0.944. Moreover, lncRNA AC129926.1 was significantly overexpressed in GC cell lines and the serum of GC patients. Importantly, colony formation, wound healing, and transwell assays further confirmed the oncogenic role of AC129926.1 in GC.

CONCLUSION

In this study, a prognostic signature model consisting of five CRLs was developed to improve OS prediction accuracy in GC patients. The model also has the potential to predict immune infiltration and immunotherapy effectiveness. Furthermore, the CRLSig might serve as a novel serum biomarker to differentiate GC patients from healthy individuals.

The mechanism of dehydroandrographolide inhibiting metastasis in gastric cancer based on network pharmacology and bioinformatics

Gastric cancer (GC) is the most aggressive malignant tumor of the digestive tract. However, there is still a lack of effective treatment methods in clinical practice. Studies have shown that dehydroandrographolide (DA) has been shown to have anti-cancer activity in a variety of cancers, but it has not been reported in GC. Firstly, we obtained data on DA target genes, GC-related genes, and differentially expressed genes (DEGs) from the PharmMapper, GeneCards, and GEO databases, respectively. Then, the STRING database was used to construct the protein-protein interaction network of intersection genes, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses of intersection genes were performed. Finally, 8 hub target genes were identified by analyzing their expression and prognostic survival, and molecular docking between the hub genes and DA was performed. In this study, 293 DA drug target genes, 11,366 GC-related genes, and 3184 DEGs were identified. Gene Ontology and KEGG analysis showed that the intersection genes of DA targets and GC-related genes were mainly related to cancer pathways involving apoptosis and cell adhesion. The intersection genes of DEGs, DA targets, and GC-related genes were also mainly related to cancer pathways involving chemical carcinogenesis, and drug metabolism. The molecular docking results showed that the 8 hub target genes had an apparent affinity for DA, which could be used as potential targets for DA treatment of GC. The results of this study show that the molecular mechanism by which DA inhibits GC metastasis involves multiple target genes. It may play an essential role in inhibiting the invasion and metastasis of GC by regulating the expression and polymorphism of hub target genes, such as MMP9, MMP12, CTSB, ESRRG, GSTA1, ADHIC, CA2, and AKR1C2.

Key Roles of p53 Signaling Pathway-Related Factors GADD45B and SERPINE1 in the Occurrence and Development of Gastric Cancer

p53 can function as an independent and unfavorable prognosis biomarker in cancer patients. We tried to identify the key factors of the p53 signaling pathway involved in gastric cancer (GC) occurrence and development based on the genotype-tissue expression (GTEx) and the Cancer Genome Atlas (TCGA) screening. We downloaded gene expression data and clinical data of GC included in the GTEx and TCGA databases, followed by differential analysis. Then, the key factors in the p53 signaling pathway were identified, followed by an analysis of the correlation between key factors and the prognosis of GC patients. Human GC cell lines were selected for in vitro cell experiments to verify the effects of key prognostic factors on the proliferation, migration, invasion, and apoptosis of GC cells. We found 4,944 significantly differentially expressed genes (DEGs), of which 2,465 were upregulated and 2,479 downregulated in GC. Then, 27 DEGs were found to be involved in the p53 signaling pathway. GADD45B and SERPINE1 genes were prognostic high-risk genes. The regression coefficients of GADD45B and SERPINE1 were positive. GADD45B was poorly expressed, while SERPINE1 was highly expressed in GC tissues, highlighting their prognostic role in GC. The in vitro cell experiments confirmed that overexpression of GADD45B or silencing of SERPINE1 could inhibit the proliferation, migration, and invasion and augment the apoptosis of GC cells. Collectively, the p53 signaling pathway-related factors GADD45B and SERPINE1 may be key genes that participate in the development of GC.

Cancer chemoresistance and its mechanisms: Associated molecular factors and its regulatory role

Cancer therapy has advanced from tradition chemotherapy methods to targeted therapy, novel drug delivery mechanisms, combination therapies etc. Although several novel chemotherapy strategies have been introduced, chemoresistance still remains as one of the major barriers in cancer treatments. Chemoresistance can lead to relapse and hinder the development of improved clinical results for cancer patients, and this continues to be the major hurdle in cancer therapy. Anticancer drugs acquire chemoresistance through different mechanisms. Understanding these mechanisms is crucial to overcome and increase the efficiency of the cancer therapies that are employed. The potential molecular pathways behind chemoresistance include tumor heterogeneity, elevated drug efflux, multidrug resistance, interconnected signaling pathways, and other factors. To surpass this limitation, new clinical tactics are to be introduced. This review aims to compile the most recent information on the molecular pathways that regulate chemoresistance in cancers, which will aid in development of new therapeutic targets and strategies.

Long noncoding RNA ZEB1-AS1 attenuates ferroptosis of gastric cancer cells through modulating miR-429/BGN axis

Gastric cancer (GC) is the fifth utmost common malignant cancer type globally, in which ferroptosis acts a critical function in the progress of GC. Long noncoding RNA ZEB1-AS1 has been recognized in numerous cancers, but the role of ZEB1-AS1 in ferroptosis remains obscure. Hence, we investigated the efficacy of ZEB1-AS1 on ferroptosis of GC cells. The cell growth and viability were analyzed via cell counting kit assay and xenograft tumor model in vivo and in vitro, respectively. The RNA and protein expression were measured by qRT-PCR and western blot analysis assay, respectively. The levels of Fe2+ , malondialdehyde (MDA), and lipid reactive oxygen species (ROS) were tested to determine ferroptosis. The erastin and RSL3 were used to induce ferroptosis. The mechanism was analyzed via luciferase reporter gene and RIP assays. The treatment of ferroptosis inducer Erastin and RSL3 suppressed the viability of GC cells and the ZEB1-AS1 overexpression rescued the phenotype in the cells. The levels of Fe2+ , MDA, and ROS were enhanced through the depletion of ZEB1-AS1 in Erastin/RSL3 treated GC cells. ZEB1-AS1 directly sponged miR-429 in GC cells and miR-429 targeted BGN in GC cells, and the inhibition of miR-429 rescued ZEB1-AS1 depletion-inhibited BGN expression. We validated that miR-429 induced and BGN-repressed ferroptosis in cancer cells. The BGN overexpression and miR-429 suppression could reverse the efficacy of ZEB1-AS1 on proliferation and ferroptosis in cancer cells. The expression of ZEB1-AS1 and BGN was enhanced and miR-429 expression was decreased in clinical GC tissues. ZEB1-AS1 attenuated ferroptosis of cancer cells by modulating miR-429/BGN axis.

Long noncoding RNAs, glucose metabolism and cancer (Review)

Cancer is a serious and potentially life-threatening disease, which, despite numerous advances over several decades, remains a challenge to treat that challenging to detect at an early stage or treat during the later stages. Long noncoding RNAs are >200 nucleotides long and do not possess protein-coding capacity, instead regulating cellular processes, such as proliferation, differentiation, maturation, apoptosis, metastasis, and sugar metabolism. Several studies have shown the role of lncRNAs and glucose metabolism in regulating several key glycolytic enzymes and the activity of multiple functional signaling pathways during tumor progression. Thus, it is possible to further learn about the effects of lncRNA and glycolytic metabolism on tumor diagnosis, treatment, and prognosis through a thorough investigation of the lncRNA expression profiles and glycolytic metabolism in tumors. This may provide a novel strategy for improving the management of several types of cancer.

RDRGSE: A Framework for Noncoding RNA-Drug Resistance Discovery by Incorporating Graph Skeleton Extraction and Attentional Feature Fusion

Identifying noncoding RNAs (ncRNAs)-drug resistance association computationally would have a marked effect on understanding ncRNA molecular function and drug target mechanisms and alleviating the screening cost of corresponding biological wet experiments. Although graph neural network-based methods have been developed and facilitated the detection of ncRNAs related to drug resistance, it remains a challenge to explore a highly trusty ncRNA-drug resistance association prediction framework, due to inevitable noise edges originating from the batch effect and experimental errors. Herein, we proposed a framework, referred to as RDRGSE (RDR association prediction by using graph skeleton extraction and attentional feature fusion), for detecting ncRNA-drug resistance association. Specifically, starting with the construction of the original ncRNA-drug resistance association as a bipartite graph, RDRGSE took advantage of a bi-view skeleton extraction strategy to obtain two types of skeleton views, followed by a graph neural network-based estimator for iteratively optimizing skeleton views aimed at learning high-quality ncRNA-drug resistance edge embedding and optimal graph skeleton structure, jointly. Then, RDRGSE adopted adaptive attentional feature fusion to obtain final edge embedding and identified potential RDRAs under an end-to-end pattern. Comprehensive experiments were conducted, and experimental results indicated the significant advantage of a skeleton structure for ncRNA-drug resistance association discovery. Compared with state-of-the-art approaches, RDRGSE improved the prediction performance by 6.7% in terms of AUC and 6.1% in terms of AUPR. Also, ablation-like analysis and independent case studies corroborated RDRGSE generalization ability and robustness. Overall, RDRGSE provides a powerful computational method for ncRNA-drug resistance association prediction, which can also serve as a screening tool for drug resistance biomarkers.

Knockdown of circADAM9 inhibits cell progression and glycolysis by targeting the miR-1236-3p/FGF7 axis in breast cancer

BACKGROUND

Circular RNAs (circRNAs) are closely associated with the development of breast cancer (BC). In this study, we aimed to clarify how differentially expressed circRNAs affect the development of BC.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circADAM9, miR-1236-3p and fibroblast growth factor 7 (FGF7). Colony formation, 5-ethynyl-2'-deoxyuridine (EdU), wound healing, transwell, and flow cytometry were used to assess cell proliferation, migration, invasion, and apoptosis. Glucose consumption, lactic acid production and ATP levels were assessed using glycolysis metabolism analysis. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were carried out to verify the relationship between miR-1236-3p and circADAM9 or FGF7. The roles of cirADAM9 on tumor growth were analyzed using a xenograft tumor model. Ki-67 and FGF7 expression was measured via immunohistochemistry (IHC) assay. Apoptosis-related proteins and exosome markers were detected by western blot.

RESULTS

CircADAM9 was highly expressed in BC cells, and circADAM9 silencing inhibited BC cell proliferation, migration, invasion, and glycolysis, and promoted cell apoptosis. Furthermore, miR-1236-3p inhibition could overturn circADAM9 knockdown-mediated BC inhibition. Moreover, the negative influences of miR-1236-3p overexpression on BC progression were restrained via FGF7 overexpression. CircADAM9 silence also inhibited BC tumor growth in vivo.

CONCLUSION

CircADAM9 promoted BC development partly by the miR-1236-3p/FGF7 axis, highlighting a potential prognostic biomarker and therapeutic target for BC patients.

Emergency exploratory laparotomy and radical gastrectomy in patients with gastric cancer combined with acute upper gastrointestinal bleeding

BACKGROUND

Gastric cancer (GC) is a prevalent malignant tumor worldwide and ranks as the fourth leading cause of cancer-related mortality. Upper gastrointestinal bleeding (UGIB) is a frequent complication of GC. Radical gastrectomy and palliative therapy are widely used surgical procedures in the clinical management of GC. This study intends to probe the clinical efficacy and safety of radical gastrectomy and palliative therapy on the basis of exploratory laparotomy in patients with GC combined with UGIB, hoping to provide valuable information to aid patients in selecting the appropriate surgical intervention.

AIM

To investigate the clinical efficacy and safety of exploratory laparotomy + radical gastrectomy and palliative therapy in patients with GC and UGIB combined.

METHODS

A total of 89 GC patients admitted to the First Affiliated Hospital of the University of South China between July 2018 and July 2020 were selected as participants for this study. The 89 patients were divided into two groups: radical resection group (n = 46) treated with exploratory laparotomy + radical gastrectomy and Palliative group (n = 43) treated with palliative therapy. The study compared several variables between the two groups, including surgical duration, intraoperative blood transfusion volume, postoperative anal exhaust time, off-bed activity time, length of hospitalization, and incidence of complications such as duodenal stump rupture, anastomotic obstruction, and postoperative incision. Additionally, postoperative immune function indicators (including CD3+, CD4+, CD8+, CD4+/CD8+, and CD3+/HLADR+), immunoglobulin (IgG and IgM), tumor markers (CEA, CA199, and CA125), and inflammatory factors (IL-6, IL-17, and TNF-α) were assessed. The surgical efficacy and postoperative quality of life recovery were also evaluated. The patients were monitored for survival and tumor recurrence at 6 mo, 1 year, and 2 years post-surgery.

RESULTS

The results indicated that the duration of operation time and postoperative hospitalization did not differ between the two surgical procedures. However, patients in the radical resection group exhibited shorter intraoperative blood loss, anus exhaust time, off-bed activity time, and inpatient activity time than those in the Palliative group. Although there was no substantial difference in the occurrence of postoperative complications, such as duodenal stump rupture and anastomotic obstruction, between the radical resection group and Palliative group (P > 0.05), the radical resection group exhibited higher postoperative immune function indicators (including CD3+, CD4+, CD8+, etc.) and immunoglobulin levels (IgG, IgM) than the Palliative group, while tumor markers and inflammatory factors levels were lower than those in the radical resection group. Additionally, surgical efficacy, postoperative quality of life, and postoperative survival rates were higher in patients who underwent radical gastrectomy than in those who underwent palliative therapy. Moreover, the probability of postoperative tumor recurrence was lower in the radical gastrectomy group compared to the palliative therapy group, and these differences were all statistically significant (P < 0.05).

CONCLUSION

Compared to palliative therapy, exploratory laparotomy + radical gastrectomy can improve immune function, reduce the levels of tumor markers and inflammatory factors, improve surgical efficacy, promote postoperative quality of life recovery, enhance survival rates, and attenuate the probability of tumor recurrence.

Jianpi Yangzheng decoction suppresses gastric cancer progression via modulating the miR-448/CLDN18.2 mediated YAP/TAZ signaling

ETHNOPHARMACOLOGICAL RELEVANCE

Developing complementary and effective drugs with less toxicity is urgent for gastric cancer (GC) therapy. Jianpi Yangzheng Decoction (JPYZ) is a curative medical plants formula against GC in clinic while its molecular mechanism remains to be further elucidated.

AIM OF THE STUDY

To evaluate the in vitro and in vivo anticancer efficacy of JPYZ against GC and its potential mechanisms.

MATERIALS AND METHODS

The effect of JPYZ on regulating the candidate targets were screened and examined by RNA-Seq, qRT-PCR, luciferase reporter assay, and immunoblotting. Rescue experiment was conducted to authenticate the regulation of JPYZ on the target gene. Molecular interaction, intracellular localization and function of target genes were elucidated via Co-IP and cytoplasmic-nuclear fractionation. The impact of JPYZ on the abundance of target gene in clinical specimens of GC patients was evaluated by IHC.

RESULTS

JPYZ treatment suppressed the proliferation and metastasis of GC cells. RNA seq revealed JPYZ significantly downregulated miR-448. A reporter plasmid containing CLDN18 3'-UTR WT exhibited significant decrease in luciferase activity when co-transfected with miR-448 mimic in GC cells. CLDN18.2 deficiency promoted the proliferation and metastasis of GC cells in vitro, as well as intensified the growth of GC xenograft in mice. JPYZ reduced the proliferation and metastasis of GC cells with CLDN18.2 abrogation. Mechanically, suppressed activities of transcriptional coactivator YAP/TAZ and its downstream targets were observed in GC cells with CLDN18.2 overexpression and those under JPYZ treatment, leading to cytoplasmic retention of phosphorylated YAP at site Ser-127. High abundance of CLDN18.2 was detected in more GC patients who received chemotherapy combined with JPYZ.

CONCLUSION

JPYZ has an inhibitory effect on GC growth and metastasis partly by elevating CLDN18.2 abundance in GC cells, indicating more patients may benefit from combination therapy of JPYZ and the upcoming CLDN18.2 target agents.

ENTPD1-AS1–miR-144-3p-mediated high expression of COL5A2 correlates with poor prognosis and macrophage infiltration in gastric cancer

BACKGROUND

Gastric cancer (GC) is a malignant tumor with high morbidity and mortality. Expression of COL5A2 is significantly elevated in GC. Abnormal expression of noncoding RNAs (ncRNAs) have been found in GC, including microRNA (miRNA) and long noncoding RNA (lncRNA). Competing endogenous RNA network plays an important regulatory role in GC. However, its specific regulatory mechanism has not been elucidated.

AIM

To gain insight into the ncRNA regulatory mechanism and immune microenvironment related to COL5A2 in GC.

METHODS

RNA sequencing data and clinical information from The Cancer Genome Atlas data portal were used to analyze the expressions of COL5A2, miRNA and lncRNA related to the prognosis of GC. Cox regression analysis and Kyoto Encyclopedia of Genes and Genomes analysis were performed to assess the risk factors and relevant function of COL5A2. StarBase was used to predict the interaction of miRNA–lncRNA or miRNA–mRNA in GC. The relationship between COL5A2, miR-144-3p and ENTPD1-AS1 were verified by dual luciferase reporter assay. The association of COL5A2 with immune cell infiltration were analyzed using the Tumor Immune Estimation Resource database and single sample gene set enrichment analysis. The expression of COL5A2 and macrophages in paired GC tissues were detected by immunohistochemical staining.

RESULTS

We verified that the upregulation of COL5A2 expression was associated with the prognosis of GC and was an independent risk factor for GC. miR-144-3p was downregulated and correlated with the prognosis of GC. miR-144-3p regulated the expression of COL5A2 through direct interaction with COL5A2. ENTPD1-AS1 was elevated in GC and competitively bound to miR-144-3p, thus inhibiting the expression of miR-144-3p. ENTPD1-AS1 enhanced the expression of COL5A2 through sponging miR-144-3p. Compared to paired normal tissue, COL5A2 expression was upregulated at the protein level, especially in the middle and late stages of GC. The high expression of COL5A2 was positively linked to macrophage infiltration in GC.

CONCLUSION

COL5A2 regulated by ENTPD1-AS1–miR-144-3p was associated with poor prognosis and macrophage infiltration in GC. This could be a new biomarker and therapeutic target in GC.

DSC2 suppresses the growth of gastric cancer through the inhibition of nuclear translocation of γ-catenin and PTEN/PI3K/AKT signaling pathway

BACKGROUND

Globally, gastric cancer (GC) is still a major leading cause of cancer-associated deaths. Downregulated desmocollin2 (DSC2) is considered to be closely related to tumor progression. However, the underlying mechanisms of DSC2 in GC progression require further exploration.

METHOD

We initially constructed different GC cells based on DSC2 contents, established the mouse tumor xenografts, and subsequently performed clonal formation, MTT, Caspase-3 activity, and sperm DNA fragmentation assays to detect the functions of DSC2 in GC growth. Subsequently, we performed western blot, Co-IP, and immunofluorescence assays to investigate the underlying mechanisms through pretreatment with PI3K inhibitor, LY294002, and its activator, recombinant human insulin-like growth factor I (IGF1).

RESULT

DSC2 could significantly inhibit the viability of GC cells at both in vitro and in vivo levels. The underlying mechanism may be that DSC2 binds the γ-catenin to decrease its nuclear level, thereby downregulating the anti-apoptotic factor BCL-2 expression and upregulating the pro-apoptotic factor P53 expression, which adjusts the PTEN/PI3K/AKT signaling pathway to promote the cancer cell apoptosis.

CONCLUSIONS

Our finding suggests that DSC2 might be a potential therapeutic target for the treatment of cancers, most especially GC.

The DNA damage repair-related lncRNAs signature predicts the prognosis and immunotherapy response in gastric cancer

Background

Gastric cancer (GC) is one of the most prevalent cancers, and it has unsatisfactory overall treatment outcomes. DNA damage repair (DDR) is a complicated process for signal transduction that causes cancer. lncRNAs can influence the formation and incidence of cancers by influencing DDR-related mRNAs/miRNAs. A DDR-related lncRNA prognostic model is urgently needed to improve treatment strategies.

Methods

The data of GC samples were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. A total of 588 mRNAs involved in DDR were selected from MSigDB, 62 differentially expressed mRNAs from TCGA-STAD were obtained, and 137 lncRNAs were correlated with these mRNAs. Univariate Cox regression and least absolute shrinkage and selection operator (LASSO) regression analyses were used to develop a DDR-related lncRNA prognostic model. Based on the risk model, the differentially expressed gene signature A/B in the low-risk and high-risk groups of TCGA-STAD was identified for further validation.

Results

The prognosis model of 5 genes (AC145285.6, MAGI2-AS3, AL590705.3, AC007405.3, and LINC00106) was constructed and classified into two risk groups. We found that GC patients with a low-risk score had a better OS than those with a high-risk score. We found that the high-risk group tended to have higher TME scores. We also found that patients in the high-risk group had a higher proportion of resting CD4 T cells, monocytes, M2 macrophages, resting dendritic cells, and resting mast cells, whereas the low-risk subgroup had a greater abundance of activated CD4 T cells, follicular helper T cells, M0 macrophages, and M1 macrophages. We observed significant differences in the T-cell exclusion score, T-cell dysfunction, MSI, and TMB between the two risk groups. In addition, we found that patients treated with immunotherapy in the low-RS score group had a longer survival and a better prognosis than those in the high-RS score group.

Conclusion

The prognostic model has a significant role in the TME, clinicopathological characteristics, prognosis, MSI, and drug sensitivity. We also discovered that patients treated with immunotherapy in the low-RS score group had a better prognosis. This work provides a foundation for improving the prognosis and response to immunotherapy among patients with GC.

LINC00426, a novel m6A-regulated long non-coding RNA, induces EMT in cervical cancer by binding to ZEB1

PURPOSE

To explore the function and molecular mechanism of LINC00426 in Cervical Cancer (CC), and to explore the clinical treatment strategy of LINC00426 for CC.

METHODS

Bioinformatics analysis was used to explore the expression of LINC00426 and patient prognosis of CC. Cell function experiments were conducted to explore the potential effect of LINC00426 on CC malignant phenotypes. The difference in m⁶A modification level between the high and low expression groups of LINC00426 was analyzed by detecting the total m⁶A level. The luciferase reporter assay was used to confirm the binding of miR-200a-3p to LINC00426. The RIP assay was used to confirm the binding of LINC00426 to ZEB1. Cell viability assay was performed to detect the effect of LINC00426 on cellular drug resistance.

RESULTS

LINC00426 is up-regulated in CC, which can enhance the proliferation, migration and invasion of CC cells. METTL3 promotes the expression of LINC00426 by m⁶A methylation modification. In addition, the LINC00426/miR-200a-3p/ZEB1 axis affects the proliferation, migration, and invasion of CC by regulating the expression of EMT markers. Through the detection of cell viability, we observed that overexpression LINC00426 in cells resulted in resistance to cisplatin and bleomycin, and more sensitive to imatinib.

CONCLUSION

LINC00426 is a cancer-promoting lncRNA related to m⁶A modification. The process of EMT in CC is regulated by the LINC00426/miR-200a/3p/ZEB1 axis. LINC00426 can affect the sensitivity of CC cells to chemotherapy drugs, and is expected to become a therapeutic target for CC.

lncSNHG3 drives breast cancer progression by epigenetically increasing CSNK2A1 expression level

Mounting evidence demonstrates that long noncoding RNAs (lncRNAs) have critical roles in the initiation and progression of cancer. Here, we report that small nucleolar RNA host gene 3 (SNHG3) is a key regulator of breast cancer progression. We analyzed RNA sequencing data to explore abnormally expressed lncRNAs in breast cancer. The effects of SNHG3 on breast cancer were investigated via in vitro and in vivo assays (CCK-8 assay, colony formation assay, flow cytometry assay, EdU assay, xenograft model, immunohistochemistry, and Western blot). The mechanism of SNHG3 action was explored through bioinformatics, RNA fluorescence in situ hybridization, luciferase reporter assay, RNA pull-down assay, chromatin immunoprecipitation assay and RNA immunoprecipitation assay. We found that SNHG3 expression was upregulated in breast cancer tissues and that its high expression level was associated with poor survival. We also found that high SNHG3 expression was partly induced by STAT3. Moreover, SNHG3 knockdown significantly repressed breast cancer cell growth both in vitro and in vivo. In the cytoplasm, SNHG3 facilitated the expression of Casein kinase II-A1 (CSNK2A1) by absorbing miR-485-5p and recruiting the HuR protein, participating in the malignant progression of breast cancer. Taken together, our study reveals a SNHG3-based regulatory network, which plays an oncogenic role in breast cancer and suggests that SNHG3 may serve as a potential target for the diagnosis and treatment of breast cancer.

LncRNA FBXO18-AS promotes gastric cancer progression by TGF-β1/Smad signaling

For the digestive system, there exists one common malignant tumor, known as gastric cancer. It is the third most prevalent type of tumor among different tumors worldwide. It has been reported that long noncoding RNAs (lncRNAs), participate in various biological processes of gastric cancer. However, there are still many lncRNAs with unknown functions, and we discovered a novel lncRNA designated as FBXO18-AS. Whether lncRNAFBXO18-AS participates in gastric cancer progression is still unknown. Bioinformatic analysis, immunohistochemistry, Western blotting, and qPCR were carried out to explore FBXO18-AS and TGF-β1 expression. In addition, EdU, MTS, migration and transwell assays were performed to investigate the invasion, proliferation and migration of gastric cancer in vitro. We first discovered that FBXO18-AS expression was upregulated in gastric cancer and linked to poorer outcomes among patients with gastric cancer. Then, we confirmed that FBXO18-AS promoted the proliferation, invasion, migration, and an EMT-like process in gastric cancer in vivo and in vitro. Mechanistically, FBXO18-AS was found to be involved in the progression of gastric cancer by modulating TGF-β1/Smad signaling. Therefore, it might offer a possible biomarker for gastric cancer diagnosis and an effective strategy for clinical treatment.

The interplay between noncoding RNAs and drug resistance in hepatocellular carcinoma: the big impact of little things

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death in people, and a common primary liver cancer. Lacking early diagnosis and a high recurrence rate after surgical resection, systemic treatment is still an important treatment method for advanced HCC. Different drugs have distinct curative effects, side effects and drug resistance due to different properties. At present, conventional molecular drugs for HCC have displayed some limitations, such as adverse drug reactions, insensitivity to some medicines, and drug resistance. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), have been well documented to be involved in the occurrence and progression of cancer. Novel biomarkers and therapeutic targets, as well as research into the molecular basis of drug resistance, are urgently needed for the management of HCC. We review current research on ncRNAs and consolidate the known roles regulating drug resistance in HCC and examine the potential clinical applications of ncRNAs in overcoming drug resistance barriers in HCC based on targeted therapy, cell cycle non-specific chemotherapy and cell cycle specific chemotherapy.

Melatonin inhibited the progression of gastric cancer induced by Bisphenol S via regulating the estrogen receptor 1

In recent years, Bisphenol S (BPS) has increasingly been used as an alternative to Bisphenol A (BPA) in food, paper, and personal care products. It is imperative to clarify the relationship between BPS and tumors in order to treat and prevent diseases. This study discovered a new method for predicting tumor correlations between BPS interactive genes. According to analyses conducted by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, interactive genes were primarily found in gastric cancer. Based on gene-targeted prediction and molecular docking, BPS appears to exert potential gastric cancer-causing effects through estrogen receptor 1 (ESR1). In addition, gastric cancer patients' prognosis could be accurately predicted by a bisphenol-based prognostic prediction model. Subsequently, the proliferation and migration abilities of gastric cancer cells were further demonstrated to be significantly enhanced by BPS. Similarly, molecular docking analysis revealed that melatonin is also highly correlated with gastric cancer and BPS. In cell proliferation and migration assays, melatonin and BPS exposure inhibited the invasion abilities of gastric cancer cells compared to BPS-exposure. Our research provided a new direction for the exploration the correlation between cancer and environmental toxicity.

Circ_0003356 suppresses gastric cancer growth through targeting the miR-668-3p/SOCS3 axis

BACKGROUND

Circular RNAs (circRNAs) have attracted extensive attention as therapeutic targets in gastric cancer (GC). Circ_0003356 is known to be downregulated in GC tissues, but its cellular function and mechanisms remain undefined.

AIM

To investigate the role of circ_0003356 in GC at the molecular and cellular level.

METHODS

Circ_0003356, miR-668-3p, and SOCS3 expression were assessed via quantitative real time-polymerase chain reaction (qRT-PCR). Wound healing, EdU, CCK-8, flow cytometry and transwell assays were used to analyze the migration, proliferation, viability, apoptosis and invasion of GC cells. The subcellular localization of circ_0003356 was monitored using fluorescence in situ hybridization. The interaction of circ_0003356 with miR-668-3p was confirmed using RIP-qRT-PCR, RNA pull-down, and dual luciferase reporter assays. We observed protein levels of genes via western blot. We injected AGS cells into the upper back of mice and performed immunohistochemistry staining for examining E-cadherin, N-cadherin, Ki67, and SOCS3 expressions. TUNEL staining was performed for the assessment of apoptosis in mouse tumor tissues.

RESULTS

Circ_0003356 and SOCS3 expression was downregulated in GC cells, whilst miR-668-3p was upregulated. Exogenous circ_0003356 expression and miR-668-3p silencing suppressed the migration, viability, proliferation, epithelial to mesenchy-mal transition (EMT) and invasion of GC cells and enhanced apoptosis. Circ_0003356 overexpression impaired tumor growth in xenograft mice. Targeting of miR-668-3p by circ_0003356 was confirmed through binding assays and SOCS3 was identified as a downstream target of miR-668-3p. The impacts of circ_0003356 on cell proliferation, apoptosis, migration, invasion and EMT were reversed by miR-668-3p up-regulation or SOCS3 down-regulation in GC cells.

CONCLUSION

Circ_0003356 impaired GC development through its interaction with the miR-668-3p/SOCS3 axis.

Genomic Landscape and Potential Regulation of RNA Editing in Drug Resistance

Adenosine-to-inosine RNA editing critically affects the response of cancer therapies. However, comprehensive identification of drug resistance-related RNA editing events and systematic understanding of how RNA editing mediates anticancer drug resistance remain unclear. Here, 7157 differential editing sites (DESs) are identified from 98 127 informative RNA editing sites in tumor tissues, many of which are validated in cancer cell lines. Diverse editing patterns of DESs are discovered in resistant samples, which could not be fully explained by adenosine deaminase acting on RNA enzymes. Some RNA-binding proteins are identified that potentially regulate these editing events. Notably, the DESs are significantly enriched in 3'-untranslated regions (3'-UTRs). The impact of DESs in 3'-UTR on the microRNA (miRNA) regulations is explored, and some triplets (DES, miRNA, and gene) that may contribute to drug resistance are identified. In addition, it is determined that the functions of genes enriched with DESs are associated with drug resistance, such as apoptosis, drug metabolism, and DNA synthesis involved in DNA repair. An online resource (http://www.jianglab.cn/REDR/) to support convenient retrieval of DESs is also built. The findings reveal the landscape and potential regulatory mechanism of RNA editing in drug resistance, providing new therapeutic targets for reversing drug resistance.

Patient-derived organoid culture of gastric cancer for disease modeling and drug sensitivity testing

BACKGROUND

Gastric cancer treatment is complicated by the molecular heterogeneity of human tumor cells, which limits the efficacy of standard therapy and necessitates the need for personalized treatment development. Patient-derived organoids (PDOs) are promising preclinical cancer models, exhibiting high clinical efficacy in predicting drug sensitivity, thus providing a new means for personalized precision medicine.

METHODS

PDOs were established from surgically resected gastric cancer tumor tissues. Molecular characterization of the tumor tissues and PDOs was performed using whole-exome sequencing analysis. Drug sensitivity tests were performed by treating the PDO cultures with 21 standard-of-care drugs corresponding to patient treatment. We evaluated whether the PDO drug phenotype reflects the corresponding patient's treatment response by comparing the drug sensitivity test results with clinical data.

RESULTS

Twelve PDOs that satisfied the drug sensitivity test criteria were successfully constructed. PDOs closely recapitulated the pathophysiology and genetic changes in the corresponding tumors, and exhibited different sensitivities to the tested drugs. In one clinical case study, the PDO accurately predicted the patient's sensitivity to capecitabine and oxaliplatin, and in a second case study the PDO successfully predicted the patient's insensitivity to S-1 chemotherapy. In summary, six of the eight cases exhibited consistency between PDO drug susceptibility test results and the clinical response of the matched patient.

CONCLUSIONS

PDO drug sensitivity tests can predict the clinical response of patients with gastric cancer to drugs, and PDOs can therefore be used as a preclinical platform to guide the development of personalized cancer treatment.

LncRNA ELFN1-AS1 upregulates TRIM29 by suppressing miR-211-3p to promote gastric cancer progression

Long noncoding RNA (lncRNA) extracellular leucine rich repeat and fibronectin type III domain containing 1-antisense RNA 1 (ELFN1-AS1) has been found to be upregulated in various tumors. However, the biological functions of ELFN1-AS1 in gastric cancer (GC) are not entirely understood. In the present study, the expression levels of ELFN1-AS1, miR-211-3p, and TRIM29 are determined using reverse transcription-quantitative PCR. Subsequently, CCK8, EdU, and colony formation assays are performed to determine GC cell vitality. The migratory and invasive capabilities of GC cells are further evaluated using transwell invasion and cell scratch assays. Western blot analysis is performed to quantify the levels of proteins associated with GC cell apoptosis and epithelialmesenchymal transition (EMT). The competing endogenous RNA (ceRNA) activity of ELFN1-AS1 on TRIM29 through miR-211-3p is confirmed by pull-down, RIP, and luciferase reporter assays. Our study proves that ELFN1-AS1 and TRIM29 are highly expressed in GC tissues. ELFN1-AS1 silencing inhibits GC cell proliferation, migration, invasion and EMT, and induces cell apoptosis. Rescue experiments reveal that the oncogenicity of ELFN1-AS1 is modulated by acting as a sponge for miR-211-3p, thereby increasing the expression of the target gene of miR-211-3p, TRIM29. In summary, ELFN1-AS1 maintains GC cell tumorigenicity via the ELFN1-AS1/miR-211-3p/TRIM29 axis, indicating that this axis can be directed for GC treatment in the future.

Advances in liquid biopsy-based markers in NSCLC

Lung cancer is the second most-frequently occurring cancer and the leading cause of cancer-associated deaths worldwide. Non-small cell lung cancer (NSCLC), the most common type of lung cancer is often diagnosed in middle or advanced stages and have poor prognosis. Diagnosis of disease at an early stage is a key factor for improving prognosis and reducing mortality, whereas, the currently used diagnostic tools are not sufficiently sensitive for early-stage NSCLC. The emergence of liquid biopsy has ushered in a new era of diagnosis and management of cancers, including NSCLC, since analysis of circulating tumor-derived components, such as cell-free DNA (cfDNA), circulating tumor cells (CTCs), cell-free RNAs (cfRNAs), exosomes, tumor-educated platelets (TEPs), proteins, and metabolites in blood or other biofluids can enable early cancer detection, treatment selection, therapy monitoring and prognosis assessment. There have been great advances in liquid biopsy of NSCLC in the past few years. Hence, this chapter introduces the latest advances on the clinical application of cfDNA, CTCs, cfRNAs and exosomes, with a particular focus on their application as early markers in the diagnosis, treatment and prognosis of NSCLC.

Novel m7G-related lncRNA signature for predicting overall survival in patients with gastric cancer

Presenting with a poor prognosis, gastric cancer (GC) remains one of the leading causes of disease and death worldwide. Long non-coding RNAs (lncRNAs) regulate tumor formation and have been long used to predict tumor prognosis. N7-methylguanosine (m7G) is the most prevalent RNA modification. m7G-lncRNAs regulate GC onset and progression, but their precise mechanism in GC is unclear. The objective of this research was the development of a new m7G-related lncRNA signature as a biomarker for predicting GC survival rate and guiding treatment. The Cancer Genome Atlas database helped extract gene expression data and clinical information for GC. Pearson correlation analysis helped point out m7G-related lncRNAs. Univariate Cox analysis helped in identifying m7G-related lncRNA with predictive capability. The Lasso-Cox method helped point out seven lncRNAs for the purpose of establishing an m7G-related lncRNA prognostic signature (m7G-LPS), followed by the construction of a nomogram. Kaplan-Meier analysis, univariate and multivariate Cox regression analysis, calibration plot of the nomogram model, receiver operating characteristic curve and principal component analysis were utilized for the verification of the risk model's reliability. Furthermore, q-PCR helped verify the lncRNAs expression of m7G-LPS in-vitro. The study subjects were classified into high and low-risk groups based on the median value of the risk score. Gene enrichment analysis confirmed the constructed m7G-LPS' correlation with RNA transcription and translation and multiple immune-related pathways. Analysis of the clinicopathological features revealed more progressive features in the high-risk group. CIBERSORT analysis showed the involvement of m7G-LPS in immune cell infiltration. The risk score was correlated with immune checkpoint gene expression, immune cell and immune function score, immune cell infiltration, and chemotherapy drug sensitivity. Therefore, our study shows that m7G-LPS constructed using seven m7G-related lncRNAs can predict the survival time of GC patients and guide chemotherapy and immunotherapy regimens as biomarker.

Prognosis Risk Model Based on Pyroptosis-Related lncRNAs for Gastric Cancer

Gastric cancer (GC) is a malignant tumor with a low survival rate, high recurrence rate, and poor prognosis. With respect to this, pyroptosis is a type of programmed cell death that can affect the occurrence and development of tumors. Indeed, long non-coding RNAs (lncRNAs) were broadly applied for the purposes of early diagnosis, treatment, and prognostic analysis in regard to cancer. Based on the association of these three purposes, we developed a novel prognosis risk model based on pyroptosis-related lncRNAs (PRlncRNAs) for GC. The PRlncRNAs were obtained via univariate and multivariate Cox regression in order to build the predictive signatures. The Kaplan–Meier and gene set enrichment analysis (GSEA) methods were used to evaluate the overall survival (OS) and functional differences between the high- and low-risk groups. Moreover, the correlation of the signatures with immune cell infiltration was determined through single-sample gene set enrichment analysis (ssGSEA). Finally, we analyzed this correlation with the treatment responses in the GC patients; then, we performed quantitative reverse transcription polymerase chain reactions (qRT-PCRs) in order to verify the risk model. The high-risk group received a worse performance in terms of prognosis and OS when compared to the low-risk group. With respect to this, the area under the receiver operating characteristic curve (ROC) was found to be 0.808. Through conducting the GSEA, it was found that the high-risk groups possessed a significant enrichment in terms of tumor–immunity pathways. Furthermore, the ssGSEA revealed that the predictive features possessed strong associations with immune cell infiltration in regard to GC. In addition, we highlighted that anti-immune checkpoint therapy, combined with conventional chemotherapy drugs, may be more suitable for high-risk patients. The expression levels of LINC01315, AP003392.1, AP000695.2, and HAGLR were significantly different between the GC cell lines and the normal cell lines. As such, the six PRlncRNAs could be regarded as important prognostic biomarkers for the purposes of subsequent diagnoses, treatments, prognostic predictions, and the mechanism research of GC.

MiR-200/183 family-mediated module biomarker for gastric cancer progression: an AI-assisted bioinformatics method with experimental functional survey

BACKGROUND

Gastric cancer (GC) is a major cancer burden throughout the world with a high mortality rate. The performance of current predictive and prognostic factors is still limited. Integrated analysis is required for accurate cancer progression predictive biomarker and prognostic biomarkers that help to guide therapy.

METHODS

An AI-assisted bioinformatics method that combines transcriptomic data and microRNA regulations were used to identify a key miRNA-mediated network module in GC progression. To reveal the module's function, we performed the gene expression analysis in 20 clinical samples by qRT-PCR, prognosis analysis by multi-variable Cox regression model, progression prediction by support vector machine, and in vitro studies to elaborate the roles in GC cells migration and invasion.

RESULTS

A robust microRNA regulated network module was identified to characterize GC progression, which consisted of seven miR-200/183 family members, five mRNAs and two long non-coding RNAs H19 and CLLU1. Their expression patterns and expression correlation patterns were consistent in public dataset and our cohort. Our findings suggest a two-fold biological potential of the module: GC patients with high-risk score exhibited a poor prognosis (p-value < 0.05) and the model achieved AUCs of 0.90 to predict GC progression in our cohort. In vitro cellular analyses shown that the module could influence the invasion and migration of GC cells.

CONCLUSIONS

Our strategy which combines AI-assisted bioinformatics method with experimental and clinical validation suggested that the miR-200/183 family-mediated network module as a "pluripotent module", which could be potential marker for GC progression.

CRISPR technology: A versatile tool to model, screen, and reverse drug resistance in cancer

BACKGROUND

Drug resistance is a serious challenge in cancer treatment that can render chemotherapy a failure. Understanding the mechanisms behind drug resistance and developing novel therapeutic approaches are cardinal steps in overcoming this issue. Clustered regularly interspaced short palindrome repeats (CRISPR) gene-editing technology has proven to be a useful tool to study cancer drug resistance mechanisms and target the responsible genes. In this review, we evaluated original research studies that used the CRISPR tool in three areas related to drug resistance, namely screening resistance-related genes, generating modified models of resistant cells and animals, and removing resistance by genetic manipulation. We reported the targeted genes, study models, and drug groups in these studies. In addition to discussing different applications of CRISPR technology in cancer drug resistance, we analyzed drug resistance mechanisms and provided examples of CRISPR's role in studying them. Although CRISPR is a powerful tool for examining drug resistance and sensitizing resistant cells to chemotherapy, more studies are required to overcome its disadvantages, such as off-target effects, immunotoxicity, and inefficient delivery of CRISPR/cas9 into the cells.

Effect of Exosomal lncRNA MALAT1/miR-370-3p/STAT3 Positive Feedback Loop on PI3K/Akt Pathway Mediating Cisplatin Resistance in Cervical Cancer Cells

Background

Exosomes can encapsulate lncRNA to mediate intercellular communication in cancer progression. Our study devoted to research the effect that long noncoding RNA Metastasis-associated lung adenocarcinoma transcript 1 (lncRNA MALAT1) influence on cervical cancer (CC).

Methods

MALAT1 and miR-370-3p levels in CC was assessed using qRT-PCR. CCK-8 assay and flow cytometry were devoted to confirm the influence on MALAT1 influencing the proliferation in cisplatin-resistant CC cells. Futher more, MALAT1, combined with miR-370-3p was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation assay.

Results

In CC tissues, MALAT1 turned into substantially expressed, cisplatin-resistant cell lines, as well as exosomes. Cell proliferation was restrained and cisplatin-induced apoptosis was promoted by way of Knockout MALAT1. And promoted the miR-370-3p level, MALAT1 targeted miR-370-3p. Promoting effect of MALAT1 on cisplatin resistance of CC was partially reversed through miR-370-3p. In addition, STAT3 may induce up-regulation of MALAT1 expression in cisplatin-resistant CC cells. It was further confirmed that the effect of MALAT1 on cisplatin-resistant CC cells was achieved by activating PI3K/Akt pathway.

Conclusion

The positive feedback loop of exosomal MALAT1/miR-370-3p/STAT3 mediates the cisplatin resistance of cervical cancer cells affecting PI3K/Akt pathway. Exosomal MALAT1 may become a promising therapeutic target for treating cervical cancer.

The Regulation of Cyclins and Cyclin-Dependent Kinases in the Development of Gastric Cancer

Gastric cancer predominantly occurs in adenocarcinoma form and is characterized by uncontrolled growth and metastases of gastric epithelial cells. The growth of gastric cells is regulated by the action of several major cell cycle regulators including Cyclins and Cyclin-dependent kinases (CDKs), which act sequentially to modulate the life cycle of a living cell. It has been reported that inadequate or over-activity of these molecules leads to disturbances in cell cycle dynamics, which consequently results in gastric cancer development. Manny studies have reported the key roles of Cyclins and CDKs in the development and progression of the disease in either in vitro cell culture studies or in vivo models. We aimed to compile the evidence of molecules acting as regulators of both Cyclins and CDKs, i.e., upstream regulators either activating or inhibiting Cyclins and CDKs. The review entails an introduction to gastric cancer, along with an overview of the involvement of cell cycle regulation and focused on the regulation of various Cyclins and CDKs in gastric cancer. It can act as an extensive resource for developing new hypotheses for future studies.

Exosomal LncRNAs in Gastrointestinal Cancer: Biological Functions and Emerging Clinical Applications

Due to the lack of specific and effective biomarkers and therapeutic targets, the early diagnosis and treatment of gastrointestinal cancer remain unsatisfactory. As a type of nanosized vesicles derived from living cells, exosomes mediate cell-to-cell communication by transporting bioactive molecules, thus participating in the regulation of many pathophysiological processes. Recent evidence has revealed that several long non-coding RNAs (lncRNAs) are enriched in exosomes. Exosomes-mediated lncRNAs delivery is critically involved in various aspects of gastrointestinal cancer progression, such as tumor proliferation, metastasis, angiogenesis, stemness, immune microenvironment, and drug resistance. Exosomal lncRNAs represent promising candidates to act as the diagnosis biomarkers and anti-tumor targets. This review introduces the major characteristics of exosomes and lncRNAs and describes the biological functions of exosomal lncRNAs in gastrointestinal cancer development. The preclinical studies on using exosomal lncRNAs to monitor and treat gastrointestinal cancer are also discussed, and the opportunities and challenges for translating them into clinical practice are evaluated.

LncRNA SNHG7 promotes non-small cell lung cancer progression and cisplatin resistance by inducing autophagic activity

Background

Cisplatin (DDP) is among the most widely used chemotherapeutic drugs for non-small cell lung cancer (NSCLC), yet the frequent emergence of chemoresistance serves as a major barrier to the treatment of this tumor type. Long non-coding RNAs (lncRNAs) have recently been shown to influence the ability of cells to resist particular chemotherapy drugs. The present study was developed to explore the role of the lncRNA SNHG7 as a regulator of NSCLC cell chemosensitivity.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to measure SNHG7 expression in NSCLC tissues from patients that were sensitive/resistant to DDP, correlations between SNHG7 expression levels and the patients' clinicopathological characteristics were assessed, and the prognostic relevance of SNHG7 expression was examined via the Kaplan-Meier approach. In addition, SNHG7 expression was assessed in NSCLC cell lines that were DDP-sensitive or -resistant, while western blotting and immunofluorescence staining were employed to detect autophagy-associated protein expression in A549, A549/DDP, HCC827, and HCC827/DDP cells. NSCLC cell chemoresistance was quantified via the Cell Counting Kit-8 (CCK-8) assay approach, and flow cytometry was used to detect the apoptotic death of these tumor cells. The chemosensitivity of xenograft tumors in vivo was further assessed to validate the functional importance of SNHG7 as a regulator of NSCLC DDP resistance.

Results

Relative to paracancerous tissues, NSCLC tumors exhibited SNHG7 upregulation, and this lncRNA was further upregulated in DDP-resistant patients compared to chemosensitive patients. Consistently, higher SNHG7 expression levels were correlated with worse patient survival outcomes. DDP-resistant NSCLC cells were also found to exhibit higher levels of SNHG7 expression than chemosensitive cells, and knocking down this lncRNA enhanced the sensitivity of these cells to DDP treatment, resulting in impaired proliferation and higher rates of apoptotic death. Knocking down SNHG7 was also sufficient to suppress microtubule associated protein 1 light chain 3 beta (LC3B) and Beclin1 protein levels and promote p62 upregulation in vitro. The silencing of this lncRNA additionally inhibited the resistance of NSCLC xenograft tumors to DDP treatment in vivo.

Conclusions

SNHG7 can promote malignant behaviors and DDP resistance in NSCLC cells at least partly via the induction of autophagic activity.

Silencing of circ_002136 sensitizes gastric cancer to paclitaxel by targeting the miR-16-5p/HMGA1 axis

The dysregulated expression of circRNA in gastric cancer (GC) induces paclitaxel (Tax) resistance of cancer cells, which in turn affects disease progression and prognosis. Here, we sought to investigate the role and mechanism of circ_002136 in Tax-resistant GC. In this study, we found the enriched circ_002136 level and the declined miR-16-5p level in Tax-resistant GC tissues and cells. Biologically, knockdown of circ_002136 elevated the Tax sensitivity of Tax-resistant GC cells, inhibited the cell motility properties, and simultaneously drove the apoptosis. Mechanically, circ_002136 promoted the HMGA1-mediated cellular Tax resistance and cell invasion by sponging miR-16-5p. Furthermore, circ_002136 silencing impeded the growth of Tax-resistant GC tumors in vivo. Overall, our study revealed a novel signaling pathway that could be used for future clinical applications, namely the circ_002136/miR-16-5p/HMGA1 axis to regulate the Tax resistance of GC cells.

Circ-ERBB2 knockdown sensitized colorectal cancer cells to 5-FU via miR-181a-5p/PTEN/Akt pathway

Colorectal cancer (CRC) is the fourth most deadly cancer worldwide, drug resistance impedes treatment of CRC. It is still urgent to find new molecular targets to improve the sensitivity of chemotherapeutic drugs. In this study, circ-ERBB2 was upregulated in CRC cells. Upregulation of circ-ERBB2 promoted CRC cells proliferation and clone formation, but inhibited apoptosis. We identified miR-181a-5p as circ-ERBB2's target. The effect of miR-181a-5p on CRC cells was contrary to circ-ERBB2, miR-181a-5p downregulation abolished the function of circ-ERBB2 silencing in CRC cells. In addition, phosphatase and tensin homolog (PTEN) was verified as miR-181a-5p's downstream target, circ-ERBB2 activates the Akt pathway and inhibits cell apoptosis through modulating miR-181a-5p/PTEN. Circ-ERBB2 silencing significantly reduced CRC cell resistance to 5-FU. miR-181a-5p downregulation abolished the role of circ-ERBB2 knockdown in CRC cell resistance to 5-FU. In conclusion, upregulation of circ-ERBB2 promoted the malignancy of CRC and reduced CRC cell resistance to 5-FU. Besides, additional mechanism study provided a novel regulatory pathways that circ-ERBB2 knockdown promoted CRC cell sensitivity to 5-FU by regulating miR-181a-5p/PTEN/Akt pathway. This research indicated that circ-ERBB2 may be a valuable biomarker for the diagnosis and treatment of CRC.

Molecular Mechanisms of Noncoding RNA in the Occurrence of Castration-Resistant Prostate Cancer

Although several therapeutic options have been shown to improve survival of most patients with prostate cancer, progression to castration-refractory state continues to present challenges in clinics and scientific research. As a highly heterogeneous disease entity, the mechanisms of castration-resistant prostate cancer (CRPC) are complicated and arise from multiple factors. Among them, noncoding RNAs (ncRNAs), the untranslated part of the human transcriptome, are closely related to almost all biological regulation, including tumor metabolisms, epigenetic modifications and immune escape, which has encouraged scientists to investigate their role in CRPC. In clinical practice, ncRNAs, especially miRNAs and lncRNAs, may function as potential biomarkers for diagnosis and prognosis of CRPC. Therefore, understanding the molecular biology of CRPC will help boost a shift in the treatment of CRPC patients. In this review, we summarize the recent findings of miRNAs and lncRNAs, discuss their potential functional mechanisms and highlight their clinical application prospects in CRPC.