Resveratrol inhibits MUC5AC expression by regulating SPDEF in lung cancer cells

BACKGROUND

MUC5AC was recently identified to play important roles in the proliferation and metastasis of malignant mucinous lung tumor cells. Resveratrol (Res), a natural compound with anticancer effects in lung cancer cells, has been reported to inhibit mucin production in airway epithelial cells. This study aimed to investigate the inhibitory effect of Res on MUC5AC expression in lung mucinous adenocarcinoma cells and the potential mechanisms.

METHODS

Mucus-producing A549 human lung carcinoma cells were used to test the effects of Res on SPDEF and MUC5AC expression. Gene and protein expression was assessed by real-time quantitative PCR (qPCR), immunofluorescence and western blotting assays. SPDEF lentivirus was used to upregulate SPDEF expression levels in mucus-producing A549 human lung carcinoma cells. Cell proliferation was assessed by Cell Counting Kit-8 (CCK-8) assay.

RESULTS

Res decreased MUC5AC expression in an SPDEF-dependent manner in mucus-producing A549 human lung carcinoma cells, and this change was accompanied by decreased ERK expression and AKT pathway activation. Moreover, SPDEF was found to be overexpressed in lung adenocarcinoma (LUAD), especially in mucinous adenocarcinoma. In-vitro functional assays showed that overexpression of SPDEF reduced the chemosensitivity of A549 cells to cisplatin (DDP). In addition, Res treatment increased A549 cell chemosensitivity to DDP by inhibiting the SPDEF-MUC5AC axis.

CONCLUSION

Our results indicate that the SPDEF-MUC5AC axis is associated with DDP sensitivity, and that Res decreases SPDEF and MUC5AC expression by inhibiting ERK and AKT signaling in A549 cells, which provides a potential pharmacotherapy for the prevention and therapeutic management of mucinous adenocarcinoma.

Establishment and characterization of an ovarian yolk sac tumor patient-derived xenograft model

OBJECTIVE

The lack of appropriate preclinical models of ovarian yolk sac tumor (OYST) is currently hindering the pursuit of new methods of treatment and investigation of the pathogenesis of the disease. We developed and characterized an OYST patient-derived xenograft (PDX) model in this study.

METHODS

Tumor fragments from a patient with an OYST were implanted subcutaneously into BALB/c Nude mice. Engrafted xenografts were compared with the original tumor according to histology, immunohistochemistry, humanized identified, and drug efficacy testing with in vivo treatment programs.

RESULTS

There was a high degree of histologic and immunohistochemical (IHC) resemblance between the established PDX model and its corresponding human tumors. Bleomycin, etoposide, and cisplatin (JEB) chemotherapy regimens were effective in clinical patients and were effective in the OYST PDX model; therefore, the effect of PDX intervention was consistent with clinical outcomes of OYSTs.

CONCLUSION

We have successfully established an OYST PDX model. This OYST model preserves the basic molecular features of the primary human tumor, thereby providing a valuable method to preclinically evaluate new treatments and explore disease pathogenesis.

Squamousness gain defines pancreatic ductal adenocarcinoma hepatic metastases phenotype, and gemcitabine response

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a dismal disease with a survival rate of less than 7%, mainly due to the hepatic metastatic spread. Despite the importance of understanding PDAC metastases, central questions remain concerning their biology and chemosensitivity. Moreover, the transcriptomic divergence between primary tumor (PT) and hepatic metastases (HM) has been poorly studied and without a clear dissection of the confounding tumoral-surrounding tissue.

METHODS

Here, to unravel key biological features not biased by the surrounding tissue, we implemented a blind source separation based on independent component analysis, ProDenICA, on a treatment-naïve cohort of PDAC paired samples and a cohort of 305 resectable patients. In addition, a time-lapse experiment was performed to assess the gemcitabine chemosensitivity profile between the PT and HM.

RESULTS

We identified HM's specific transcriptomic characteristics related to the upregulation of cell cycle checkpoint, mitochondria activity, and extracellular matrix reorganization, which could be associated with metastatic niche adaptation mechanisms. Furthermore, squamous lineage emerged as a key feature linked with a downregulation in the epithelial-to-mesenchymal program that can stratifies PDAC HM independent of the classical/basal-like spectrum. Remarkably, we also demonstrated that gemcitabine response is influenced by the squamous profile, being the HM more refractory to the treatment than the PT.

CONCLUSIONS

These results pointed out divergent HM aspects compared to PT and allowed their stratification through the squamous lineage. Moreover, we unravel a clinical actionable squamous signature that predicts the gemcitabine response.

Targeting WD repeat domain 5 enhances chemosensitivity and inhibits proliferation and programmed death-ligand 1 expression in bladder cancer

Background

Chemotherapy and/or immunotherapy are first-line treatments for advanced muscle-invasive bladder cancer (BCa), but the unsatisfactory objective response rate to these treatments yields poor 5-year patient survival. Discovery of therapeutic targets essential for BCa maintenance is critical to improve therapy response in clinic. This study evaluated the role of targeting WD repeat domain 5 (WDR5) with the small molecule compound OICR-9429 and whether it could be used to treat bladder cancer.

Methods

We analysed the expression and clinical prognosis of WDR5 in a TCGA cohort. The pharmacological role of OICR-9429 was further investigated in vitro and in vivo. RNA sequencing, western blot, and chromatin immunoprecipitation (ChIP) were utilized to explored the mechanism underlying OICR-9429-induced WDR5 inhibition.

Results

First, we found that WDR5 expression was upregulated in BCa and was associated with histologic grade, metastasis status, histologic subtype, and molecular subtype. High WDR5 expression level was also correlated with shorter overall survival (OS) in BCa. The WDR5 inhibitor OICR-9429 reduced cell viability by decreasing H3K4me3 levels but not WDR5 levels in T24, UM-UC-3, and TCCSUP BCa cells. OICR-9429 suppressed the proliferation of BCa cells by blocking the G1/S phase transition. Next, OICR-9429 enhanced apoptosis and chemosensitivity to cisplatin in BCa cells. In addition, OICR-9429 independently inhibited the motility and metastatic behaviour of BCa cells. In vivo experiments further revealed that OICR-9429 suppressed tumour growth, enhanced chemosensitivity, and reduced the toxicity of cisplatin in BCa. Notably, WDR5 was positively correlated with programmed death-ligand 1 (PD-L1) expression, and OICR-9429 suppressed immune evasion by blocking PD-L1 induced by IFN-γ. Mechanistically, some cell cycle-, antiapoptosis-, DNA repair-, metastasis-, and immune evasion-related genes, including BIRC5, XRCC2, CCNB1, CCNE2, PLK1, AURKA, FOXM1, and PD-L1 were identified to be directly regulated by OICR-9429 in a H3K4me3-dependent manner.

Conclusions

Our novel finding is that the WDR5 inhibitor, OICR-9429, suppressed proliferation, metastasis and PD-L1-based immune evasion while enhancing apoptosis and chemosensitivity to cisplatin in BCa by blocking the WDR5-MLL complex mediating H3K4me3 in target genes. Hence, our findings offer insight into a multipotential anticancer compound, OICR-9429, which enhances the antitumour effect of cisplatin or immunotherapy in BCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01989-5.

Retinoblastoma tumor suppressor gene 1 enhances 5-Fluorouracil chemosensitivity through SDF-1/CXCR4 axis by regulating autophagy in gastric cancer

Due to lack of effective biomarkers for early diagnosis, most patients are diagnosed with advanced gastric cancer and have lower survival rates. 5-Fluorouracil (5-FU) is one of commonly used drugs for chemotherapy of gastric cancer, but drug resistance limits the wide application of agents. Retinoblastoma tumor suppressor gene 1 (RB1) is a key regulator in the progression of various human cancers, including gastric cancer. However, the effects of RB1 on chemosensitivity and the underlying mechanisms in gastric cancer (GC) are not clear. In this study, expressions of RB1 in GC cell lines were evaluated by RT-qPCR and western blot assay. CCK-8 was applied to examine the effect of 5-FU on cell viability. Meanwhile, IC50 values were calculated. The drug-resistance protein MDR1 and autophagy-related proteins were detected by western blot assay. Flow cytometry was used to detect cell cycle. The results showed that RB1 expressions were downregulated in GC cell lines and had significant differences between 5-FU resistance cell lines (SNU-620/5-FU and NUGC-3/5-FU) and non-resistance cell lines (SNU-620 and NUGC-3). Overexpression of RB1 enhanced 5-FU sensitivity of GC cells and caused cell cycle arrest in the S phase. Meanwhile, autophagy-related proteins were downregulated. Mechanistically, SDF-1/CXCR4 participated in the regulation of RB1 on cell autophagy. Autophagy activator, SDF-1 treatment and CXCR4 activation reversed the promoted effects of RB1 on 5-FU sensitivity in GC cells. In conclusion, our data revealed that RB1 was downregulated in GC cell lines. RB1 overexpression enhanced 5-FU chemosensitivity in GC cells by regulating cell autophagy via SDF-1/CXCR4 pathway. RB1 might serve as a promising therapeutic target of GC.

Breath-holding as a novel approach to risk stratification in COVID-19

BACKGROUND

Despite considerable progress, it remains unclear why some patients admitted for COVID-19 develop adverse outcomes while others recover spontaneously. Clues may lie with the predisposition to hypoxemia or unexpected absence of dyspnea ('silent hypoxemia') in some patients who later develop respiratory failure. Using a recently-validated breath-holding technique, we sought to test the hypothesis that gas exchange and ventilatory control deficits observed at admission are associated with subsequent adverse COVID-19 outcomes (composite primary outcome: non-invasive ventilatory support, intensive care admission, or death).

METHODS

Patients with COVID-19 (N = 50) performed breath-holds to obtain measurements reflecting the predisposition to oxygen desaturation (mean desaturation after 20-s) and reduced chemosensitivity to hypoxic-hypercapnia (including maximal breath-hold duration). Associations with the primary composite outcome were modeled adjusting for baseline oxygen saturation, obesity, sex, age, and prior cardiovascular disease. Healthy controls (N = 23) provided a normative comparison.

RESULTS

The adverse composite outcome (observed in N = 11/50) was associated with breath-holding measures at admission (likelihood ratio test, p = 0.020); specifically, greater mean desaturation (12-fold greater odds of adverse composite outcome with 4% compared with 2% desaturation, p = 0.002) and greater maximal breath-holding duration (2.7-fold greater odds per 10-s increase, p = 0.036). COVID-19 patients who did not develop the adverse composite outcome had similar mean desaturation to healthy controls.

CONCLUSIONS

Breath-holding offers a novel method to identify patients with high risk of respiratory failure in COVID-19. Greater breath-hold induced desaturation (gas exchange deficit) and greater breath-holding tolerance (ventilatory control deficit) may be independent harbingers of progression to severe disease.

[Effect of miR-23b on the malignant phenotype and the sensitivity of lenvatinib in human hepatocellular carcinoma cells]

Objective: To investigate the effect of miR-23b on the malignant phenotype and the sensitivity of lenvatinib in human hepatocellular carcinoma cells. Methods: Human hepatocellular carcinoma cell line HepG2, SMMC-7721 and QGY-7703 were transfected with miR-23b mimic and its control, respectively. CCK-8 and EdU assay were used to detect cell proliferation. Transwell assay were used to detect changes in cell migration and invasion. Tube formation assay were used to detect vasculogenic mimicry formation. The comparison of the mean between groups was analyzed by t-test. Results: CCK-8 results showed that the A values ​​of human hepatocellular carcinoma cell line HepG2 and SMMC-7721 in the miR-23b mimic group were 0.325 ± 0.011 and 0.537 ± 0.026, respectively, which were significantly lower than the control group 0.430±0.017 and 0.752 ± 0.051 (P < 0.05). Transwell assay result showed that the number of cell migration of human hepatocellular carcinoma cell line HepG2 and SMMC-7721 in the miR-23b mimic group was (517.220 ± 32.873) and (242.327 ± 20.793), respectively, which were significantly lower than that of the control group (724.130 ± 15.142) and (424.432 ± 27.212) (P < 0.01). Simultaneously, the number of cell invasions in the miR-23b mimic group were (55.671 ± 7.514) and (64.670 ± 6.011), respectively, which were significantly lower than those in the control group (124.320 ± 11.782) and (156.204 ± 12.501) (P < 0.01). Tube formation assay showed that the number of tube forming branches of hepatocellular carcinoma cell line QGY-7703 and SMMC-7721 in the miR-23b mimic group was (489.824 ± 42.035) and (435.201 ± 44.143), respectively, which were significantly lower than that of the control group (878.620 ± 31.618) and (785.430 ± 38.723) (P ​​< 0.01). In addition, EdU results showed that after miR-23b combined with lenvatinib, the positive rates of EdU staining of hepatocellular carcinoma cell line HepG2 and SMMC-7721 in the miR-23b mimic group were (32.905 ± 1.342)% and (24.811 ± 0.820)%, respectively, which were significantly lower than the control group (52.623 ± 2.441)% and (38.702 ± 1.312)% (P < 0.05). Conclusion: miR-23b can inhibit the proliferation, migration, invasion and vasculogenic mimicry formation, and enhance the sensitivity of lenvatinib drug in human hepatocellular carcinoma cells.

B16 melanomas evade antitumor immunity by the loss of epitope presentation and the acquisition of tumor resistance to granzyme B

Melanomas exhibit the highest rate of heterogeneity among cancer cell types. In this study, we tested the two types of B16 melanoma cells (B16-S0-1 and B16-S1-1) showing resistance to antitumor immunity. These cells expressed Trp2 protein. Contrary to B16 and B16-S0-1 cells, B16-S1-1 cells failed to stimulate IFN-γ responses in Trp2-specific CD8+ T cells, suggesting that B16-S1-1 cells may have lost the ability to present antigen to Ag-specific CTLs in the context of MHC class I molecules. However, B16-S0-1 cells exhibited active Stat3 and decreased Bcl-2 expression, which were found to be not associated with immune escape. B16-S0-1 cells were more resistant to granzyme B-mediated caspase activation and apoptosis than B16 cells. Thus, these data show that B16 cells escape antitumor immune responses through the loss of epitope presentation to CTLs and the acquisition of tumor cell resistance to granzyme B-mediated caspase activation.

Fat mass and obesity-associated protein (FTO) mediates signal transducer and activator of transcription 3 (STAT3)-drived resistance of breast cancer to doxorubicin

Excessive activation of signal transducer and activator of transcription 3 (STAT3) is implicated in breast cancer (BC) chemoresistance, but its underlying mechanism is not fully understood. There are STAT3 binding sites in fat mass and obesity-associated protein (FTO) promoter region, thus STAT3 may regulate the transcription of FTO. This study aimed to investigate the correlation between FTO and STAT3 in BC chemoresistance. Herein, FTO and STAT3 were highly expressed in doxorubicin-resistant BC (BC-DoxR) cells. CHIP assay verified the binding between STAT3 and FTO promoter in BC-DoxR cells. Dual luciferase reporter assay showed that FTO promoter activity was inhibited by S3I-201 (STAT3 inhibitor) but enhanced by epidermal growth factor (EGF, STAT3 activator) in BC-DoxR and BC cells. FTO mRNA and protein expression were suppressed by S3I-201 in BC-DoxR cells and EGF-stimulated BC cells. Notably, FTO regulated total N6-methyladenosine (m6A) levels in BC-DoxR and BC cells but could not affect STAT3 mRNA expression, indicating that FTO was not involved in the m6A modification of STAT3. However, FTO could activate STAT3 signaling in BC-DoxR and BC cells. Besides, FTO knockdown inhibited the doxorubicin resistance of BC-DoxR cells, while FTO overexpression enhanced the doxorubicin resistance and weakened the doxorubicin sensitivity of BC cells. Moreover, decreased doxorubicin resistance by STAT3 knockdown was abolished by FTO overexpression and decreased doxorubicin sensitivity by STAT3 overexpression was reversed by FTO knockdown, indicating that FTO was implicated in STAT3-mediated doxorubicin resistance and impairment of doxorubicin sensitivity of BC cells. Altogether, our findings provide a mechanism underlying BC doxorubicin resistance.

Identification of biological targets through the correlation between cell line chemosensitivity and protein expression pattern

Matching biological data sequences is one of the most interesting ways to discover new bioactive compounds. In particular, matching cell chemosensitivity with a protein expression profile can be a useful approach to predict the activity of compounds against definite biological targets. In this review, we discuss this correlation. First, we analyze case studies in which some known drugs, acting on known targets, show a good correlation between their antiproliferative activities and protein expression when a large panel of tumor cells is considered. Then, we highlight how the application of in silico methods based on the correlation between cell line chemosensitivity and gene/protein expression patterns might be a quick, cheap, and interesting approach to predict the biological activity of investigated molecules.

MicroRNA-1: Diverse role of a small player in multiple cancers

The process of cancer initiation and development is a dynamic and complex mechanism involving multiple genetic and non-genetic variations. With the development of high throughput techniques like next-generation sequencing, the field of cancer biology extended beyond the protein-coding genes. It brought the functional role of noncoding RNAs into cancer-associated pathways. MicroRNAs (miRNAs) are one such class of noncoding RNAs regulating different cancer development aspects, including progression and metastasis. MicroRNA-1 (miR-1) is a highly conserved miRNA with a functional role in developing skeletal muscle precursor cells and cardiomyocytes and acts as a consistent tumor suppressor gene. In humans, two discrete genes, MIR-1-1 located on 20q13.333 and MIR-1-2 located on 18q11.2 loci encode for a single mature miR-1. Downregulation of miR-1 has been demonstrated in multiple cancers, including lung, breast, liver, prostate, colorectal, pancreatic, medulloblastoma, and gastric cancer. A vast number of studies have shown that miR-1 affects the hallmarks of cancer like proliferation, invasion and metastasis, apoptosis, angiogenesis, chemosensitization, and immune modulation. The potential therapeutic applications of miR-1 in multiple cancer pathways provide a novel platform for developing anticancer therapies. This review focuses on the different antitumorigenic and therapeutic aspects of miR-1, including how it regulates tumor development and associated immunomodulatory functions.

Cell membrane permeability and defective G2/M block as factors potentially contributing to increased cell chemosensitivity. SeAx cell line as an example

Background

Immortalized mammalian cell lines are a valuable research tool, though they represent a highly simplified model. Due to accumulated mutations they may not reflect characteristics of the disease or even the tissue they derive from.

Objective

We aim to pinpoint factors distinguishing SeAx cells from two other cutaneous T-cell lymphoma (CTCL) cell lines, namely Hut78 and MyLa2000. Of note, these factors may influence cell sensitivity in an unspecific way and therefore should be taken under consideration.

Methods

We evaluated transcriptional levels of drug transporters across cell lines, cell membrane permeability, functionality of pathways related to DNA damage response and activation of G2/M block.

Results

Analysis of the transcriptional levels of genes coding drug efflux pumps indicated that they are not consistently down-regulated in SeAx. However, we noted that SeAx cell membrane is markedly more permeable than Hut78 and MyLa2000, which may contribute to increased chemosensitivity in an unspecific way.

Moreover, though DNA damage response seemed to be at least partly functional in SeAx cells, they fail to activate G2/M block in response to psoralen + UVA treatment. Any DNA damage should be repaired before cells enter mitosis, in order to uphold genome integrity. Thus, a defective cell cycle block may contribute to cell sensitivity.

Conclusions

We believe that factors such as increased membrane permeability or defective cell cycle block should be accounted for when comparing sensitivity of cell line panels to chemotherapeutics of interest. It is worth to exclude a simple, indiscriminative mechanisms of cell resistance or sensitivity before attempting comparisons. Cell lines that are indiscriminately sensitive to a broad range of chemicals may contribute to overestimating the cytotoxic potential of tested compounds if used in cytotoxicity studies.

•

Mammalian cell lines are a valuable, but highly simplified model.

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Cell chemosensitivity and resistance may have specific or unspecific character.

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SeAx cell line exhibits higher chemosensitivity than other tested CTCL cell lines.

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SeAx chemosensitivity may result from high membrane permeability and/or defective G2/M block.

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Unspecific mechanisms of cell sensitivity or resistance may lead to false conclusions.

Low curcumin concentration enhances the anticancer effect of 5-fluorouracil against colorectal cancer

BACKGROUND

Colon cancer treatments include surgery, radiotherapy, and chemotherapy. Chemotherapy using 5-fluorouracil (5-FU) has been widely applied to treat colorectal cancer (CRC). However, it is important to explore the use of chemotherapy drugs in combination with other agents to decrease severe adverse effects.

PURPOSE

This study aimed to investigate the effects of curcumin in combination with 5-FU on the proliferation, migration, and apoptosis of CRC SW620 cell line both in vitro and in vivo.

METHODS

Flow cytometry was used to study the effect of curcumin on chemotherapy-induced apoptosis in CRC cells. The mechanism of curcumin's enhanced antitumor effect in vivo was investigated using gene knockdown, TUNEL, western blot, qRT-PCR and immunohistochemistry.

RESULTS

The results showed a synergistic effect of the two compounds on CRC cells. Considerable reduction in the proliferation and migration of SW620 cells was observed in the combination treatment group. Significantly increased apoptosis rate extended the survival of immunodeficient mice in the combination group as compared to that of the 5-FU group (p < 0.05). The results showed that curcumin significantly inhibited pERK signaling and downregulated L1 expression in SW620 cells.

CONCLUSIONS

We conclude that curcumin promotes chemosensitivity of CRC cells to 5-FU by downregulating L1 expression. Our findings provide experimental evidence for the synergism between curcumin and 5-FU, which can be utilized in clinical applications for reducing the toxicity and adverse effects of 5-FU.

SPARC enhances 5-FU chemosensitivity in gastric cancer by modulating epithelial-mesenchymal transition and apoptosis

Previous studies have shown that secreted protein acidic and rich in cysteine (SPARC) proteins can inhibit the development of cancer cells in various ways, such as by inhibiting angiogenesis and inhibiting cell proliferation. In fact, SPARC proteins may have an effect on the chemoresistance of gastric cancer cells to 5-Fluorouracil (5-FU), which needs further research in the future. Therefore, the purpose of this study was to explore the relationship between SPARC proteins and the chemosensitivity of gastric cancer cells to 5-FU. In vitro, after SPARC protein levels were regulated by plasmid, siRNA and human recombinant SPARC protein transfection in MGC-803, SGC-7901 and BGC-823 cells, we detected epithelial-mesenchymal transition (EMT), apoptosis markers and cell viability after 5-FU treatment. In vivo, we implanted BGC-823 cells with stable SPARC overexpression into nude mice. Tumour size was measured to assess the effect of SPARC protein on tumour formation and 5-FU chemosensitivity. In SGC-7901 and BGC-823 cells, both endogenous and exogenous upregulation of SPARC protein levels decreased cell viability, destroyed cytoskeletal F-actin, inhibited cell migration, and downregulated a series of transcription factors to inhibit cell EMT; it also upregulated cell apoptosis-related proteins to promote cell apoptosis. However, we obtained opposite results in SPARC knockdown MGC-803 cells. In vivo, compared with the control group, the group engrafted with BGC-823 cells stably overexpressing SPARC had a significant smaller tumour size. After 5-FU treatment, the new tumour gradually decreased in size. Our results show that the SPARC protein could enhance 5-FU chemosensitivity in gastric cancer cell lines by inhibiting EMT and promoting cell apoptosis.

Tenascin C Promotes Glioma Cell Malignant Behavior and Inhibits Chemosensitivity to Paclitaxel via Activation of the PI3K/AKT Signaling Pathway

The present study aimed to detect the effect of tenascin C (TNC) on cell function and chemosensitivity to paclitaxel and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling in glioma cells.Human glioma cells U87, LN-229, T98G and U251 and normal human astrocytes were obtained, in which TNC expression was detected. The U87 cells and U251 cells were chosen and infected with lentivirus of control overexpression, TNC overexpression, control knockdown, and TNC knockdown for functional experiments. Rescue experiments were then performed to evaluate the effect of PI3K/AKT activator 740 Y-P on cell function and chemosensitivity to paclitaxel in TNC knockdown U251 cells. TNC mRNA and protein expression was elevated in glioma cells, including U87, LN-229, U251 and T98G cells, compared to normal human astrocytes. In U87 and U251 cells, TNC promoted proliferation while inhibiting apoptosis. In addition, TNC upregulated PI3K and p-AKT protein expression in U87 and U251 cells. As for chemosensitivity, TNC increased relative viability in U251 cells treated with 400 ng/mL and 800 ng/mL paclitaxel. In terms of stemness, TNC increased the sphere number per 1000 cells, CD44⁺CD133⁺ cell percentage and 1/stem cell frequency (assessed by extreme limiting dilution analysis) in U251 cells. In rescue experiments, 740 Y-P reduced the effect of TNC on proliferation, apoptosis, chemosensitivity to paclitaxel, and stemness in U251 cells. TNC acts as an oncogenic factor by promoting cancer cell proliferation and stemness while inhibiting apoptosis and chemosensitivity to paclitaxel in glioma via modulation of PI3K/AKT signaling.

Sec62 promotes stemness and chemoresistance of human colorectal cancer through activating Wnt/β-catenin pathway

BACKGROUND

Cancer stem cell (CSC)-related chemoresistance leads to poor outcome of the patients with colorectal cancer (CRC). In this study, we identified the chemoresistance-relevant molecules and decipher the involved mechanisms to provide potential therapeutic target for CRC. We focused on Sec62, a novel target with significantly increased expression in chemoresistant CRC tissues, and further investigated its role in the progression of CRC.

METHODS

Through analyzing the differentially-expressed genes between chemoresistant and chemosensitive CRCs, we selected Sec62 as a novel chemoresistance-related target in CRC. The expression and clinical significance of Sec62 were determined by immunoblotting and immunohistochemistry in tissues and cell lines of CRC. The roles of Sec62 in drug resistance, stemness and tumorigenesis were evaluated in vitro and in vivo using functional experiments. GST pull-down, western blot, coimmunoprecipitation and Me-RIP assays were performed to further explore the downstream molecular mechanisms.

RESULTS

Sec62 upregulation was associated with the chemoresistance of CRC and poor outcome of CRC patients. Depletion of Sec62 sensitized CRC cells to chemotherapeutic drugs. Sec62 promoted the stemness of CRC cells through activating Wnt/β-catenin signaling. Mechanistically, Sec62 bound to β-catenin and inhibited the degradation of β-catenin. Sec62 competitively disrupted the interaction between β-catenin and APC to inhibit the β-catenin destruction complex assembly. Moreover, Sec62 expression was upregulated by the m6A-mediated stabilization of Sec62 mRNA.

CONCLUSIONS

Sec62 upregulated by the METTL3-mediated m6A modification promotes the stemness and chemoresistance of CRC by binding to β-catenin and enhancing Wnt signalling. Thus, m6A modification-Sec62-β-catenin molecular axis might act as therapeutic targets in improving treatment of CRC.

Metabolomic profiling of pancreatic adenocarcinoma reveals key features driving clinical outcome and drug resistance

BACKGROUND

Although significant advances have been made recently to characterize the biology of pancreatic ductal adenocarcinoma (PDAC), more efforts are needed to improve our understanding and to face challenges related to the aggressiveness, high mortality rate and chemoresistance of this disease.

METHODS

In this study, we perform the metabolomics profiling of 77 PDAC patient-derived tumor xenografts (PDTX) to investigate the relationship of metabolic profiles with overall survival (OS) in PDAC patients, tumor phenotypes and resistance to five anticancer drugs (gemcitabine, oxaliplatin, docetaxel, SN-38 and 5-Fluorouracil).

FINDINGS

We identified a metabolic signature that was able to predict the clinical outcome of PDAC patients (p < 0.001, HR=2.68 [95% CI: 1.5-4.9]). The correlation analysis showed that this metabolomic signature was significantly correlated with the PDAC molecular gradient (PAMG) (R = 0.44 and p < 0.001) indicating significant association to the transcriptomic phenotypes of tumors. Resistance score established, based on growth rate inhibition metrics using 35 PDTX-derived primary cells, allowed to identify several metabolites related to drug resistance which was globally accompanied by accumulation of several diacy-phospholipids and decrease in lysophospholipids. Interestingly, targeting glycerophospholipid synthesis improved sensitivity to the three tested cytotoxic drugs indicating that interfering with metabolism could be a promising therapeutic strategy to overcome the challenging resistance of PDAC.

INTERPRETATION

In conclusion, this study shows that the metabolomic profile of pancreatic PDTX models is strongly associated to clinical outcome, transcriptomic phenotypes and drug resistance. We also showed that targeting the lipidomic profile could be used in combinatory therapies against chemoresistance in PDAC.

Impact of ovariectomy and CO2 inhalation on microglia morphology in select brainstem and hypothalamic areas regulating breathing in female rats

The neural network that regulates breathing shows a significant sexual dimorphism. Ovarian hormones contribute to this distinction as, in rats, ovariectomy reduces the ventilatory response to CO2. Microglia are neuroimmune cells that are sensitive to neuroendocrine changes in their environment. When reacting to challenging conditions, these cells show changes in their morphology that reflect an augmented capacity for producing pro- and anti-inflammatory cytokines. Based on evidence suggesting that microglia contribute to sex-based differences in reflexive responses to hypercapnia, we hypothesized that ovariectomy and hypercapnia promote microglial reactivity in selected brain areas that regulate breathing. We used ionized calcium-binding-adapter molecule-1 (Iba1) immunolabeling to compare the density and morphology of microglia in the locus coeruleus (LC), the caudal medullary raphe, the caudal part of the nucleus of the tractus solitarius (cNTS), and the paraventricular nucleus of the hypothalamus (PVN). Tissue was obtained from SHAM (metaestrus) female rats or following ovariectomy. Rats were exposed to normocapnia or hypercapnia (5% CO2, 20 min). Ovariectomy and hypercapnia did not affect microglial density in any of the structures studied. Ovariectomy promoted a reactive phenotype in the cNTS and LC, as indicated by a larger morphological index. In these structures, hypercapnia had a relatively modest opposing effect; the medullary raphe or the PVN were not affected. We conclude that ovarian hormones attenuate microglial reactivity in CO2/H+ sensing structures. These data suggest that microglia may contribute to neurological diseases in which anomalies of respiratory control are associated with cyclic fluctuations of ovarian hormones or menopause.

MIR600HG suppresses metastasis and enhances oxaliplatin chemosensitivity by targeting ALDH1A3 in colorectal cancer

Background: Metastasis and chemoresistance indicate a poor prognosis in colorectal cancer (CRC) patients. However, the mechanisms that lead to the development of chemoresistance and metastasis in CRC remain unclear.

Materials and methods: We combined clinical and experimental studies to determine the role of MIR600HG in CRC metastasis and chemoresistance. The statistical analysis was performed using GraphPad Prism software, version 8.0.

Results: We detected down-regulated expression of long non-coding RNA (lncRNA) MIR600HG in CRC specimens and cell lines compared with normal controls, and the expression level of MIR600HG was inversely correlated with the overall survival of CRC patients. The inhibition of MIR600HG stimulated CRC cell metastasis and chemoresistance. In addition, our data showed that the inhibition of MIR600HG stimulated CRC stemness, while the overexpression of MIR600HG suppressed stemness. Importantly, our animal experiments showed that MIR600HG inhibited tumour formation and that the combination of MIR600HG inhibition and oxaliplatin (Oxa) treatment significantly inhibited tumour growth compared with that with either intervention alone. Furthermore, we demonstrated that MIR600HG exerts its anticancer role by targeting ALDH1A3 in CRC.

Conclusions: Our data suggest that MIR600HG functions as a tumour suppressor and that the overexpression of MIR600HG inhibits tumour invasion and enhances chemosensitivity, providing a new strategy for CRC treatment.

Long non-coding RNAs in the doxorubicin resistance of cancer cells

Chemotherapy is the main treatment used for cancer patients failing surgery. Doxorubicin (DOX) is a well-known chemotherapeutic agent capable of suppressing proliferation in cancer cells and triggering apoptosis via inhibiting topoisomerase II activity and producing DNA breaks. This activity of DOX restrains mitosis and cell cycle progression. However, frequent application of DOX results in the emergence of resistance in the cancer cells. It seems that genetic and epigenetic factors can provide DOX resistance of cancer cells. Long non-coding RNAs (lncRNAs) are a subcategory of non-coding RNAs with role in the regulation of several cellular processes such as proliferation, migration, differentiation and apoptosis. LncRNA dysregulation has been associated with chemoresistance, and this profile occurs upon DOX treatment of cancer. In the present review, we focus on the role of lncRNAs in mediating DOX resistance and discuss the molecular pathways and mechanisms. LncRNAs can drive DOX resistance via activating pathways such as NF-κB, PI3K/Akt, Wnt, and FOXC2. Some lncRNAs can activate protective autophagy in response to the stress caused by DOX, which mediates resistance. In contrast, there are other lncRNAs involved in the sensitivity of cancer cells to DOX, such as GAS5, PTCSC3 and FENDRR. Some anti-tumor agents such as polydatin can regulate the expression of lncRNAs, enhancing DOX sensitivity. Overall, lncRNAs are potential players in DOX resistance, and their identification and targeting are of importance in chemosensitivity. Furthermore, these findings can be translated into clinical for treatment of cancer patients.

Inhibition of EZH2 by chidamide exerts antileukemia activity and increases chemosensitivity through Smo/Gli-1 pathway in acute myeloid leukemia

Background

Epigenetic dysregulation plays important roles in leukemogenesis and the progression of acute myeloid leukemia (AML). Histone acetyltransferases (HATs) and histone deacetylases (HDACs) reciprocally regulate the acetylation and deacetylation of nuclear histones. Aberrant activation of HDACs results in uncontrolled proliferation and blockade of differentiation, and HDAC inhibition has been investigated as epigenetic therapeutic strategy against AML.

Methods

Cell growth was assessed with CCK-8 assay, and apoptosis was evaluated by flow cytometry in AML cell lines and CD45 + and CD34 + CD38- cells from patient samples after staining with Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI). EZH2 was silenced with short hairpin RNA (shRNA) or overexpressed by lentiviral transfection. Changes in signaling pathways were detected by western blotting. The effect of chidamide or EZH2-specific shRNA (shEZH2) in combination with adriamycin was studied in vivo in leukemia-bearing nude mouse models.

Results

In this study, we investigated the antileukemia effects of HDAC inhibitor chidamide and its combinatorial activity with cytotoxic agent adriamycin in AML cells. We demonstrated that chidamide suppressed the levels of EZH2, H3K27me3 and DNMT3A, exerted potential antileukemia activity and increased the sensitivity to adriamycin through disruption of Smo/Gli-1 pathway and downstream signaling target p-AKT in AML cells and stem/progenitor cells. In addition to decreasing the levels of H3K27me3 and DNMT3A, inhibition of EZH2 either pharmacologically by chidamide or genetically by shEZH2 suppressed the activity of Smo/Gli-1 pathway and increased the antileukemia activity of adriamycin against AML in vitro and in vivo.

Conclusions

Inhibition of EZH2 by chidamide has antileukemia activity and increases the chemosensitivity to adriamycin through Smo/Gli-1 pathway in AML cells (Fig. 5). These findings support the rational combination of HDAC inhibitors and chemotherapy for the treatment of AML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02789-3.

Sulfasalazine modifies metabolic profiles and enhances cisplatin chemosensitivity on cholangiocarcinoma cells in in vitro and in vivo models

Background

Sulfasalazine (SSZ) is widely known as an xCT inhibitor suppressing CD44v9-expressed cancer stem-like cells (CSCs) being related to redox regulation. Cholangiocarcinoma (CCA) has a high recurrence rate and no effective chemotherapy. A recent report revealed high levels of CD44v9-positive cells in CCA patients. Therefore, a combination of drugs could prove a suitable strategy for CCA treatment via individual metabolic profiling.

Methods

We examined the effect of xCT-targeted CD44v9-CSCs using sulfasalazine combined with cisplatin (CIS) or gemcitabine in CCA in vitro and in vivo models and did NMR-based metabolomics analysis of xenograft mice tumor tissues.

Results

Our findings suggest that combined SSZ and CIS leads to a higher inhibition of cell proliferation and induction of cell death than CIS alone in both in vitro and in vivo models. Xenograft mice showed that the CD44v9-CSC marker and CK-19-CCA proliferative marker were reduced in the combination treatment. Interestingly, different metabolic signatures and significant metabolites were observed in the drug-treated group compared with the control group that revealed the cancer suppression mechanisms.

Conclusions

SSZ could improve CCA therapy by sensitization to CIS through killing CD44v9-positive cells and modifying the metabolic pathways, in particular tryptophan degradation (i.e., kynurenine pathway, serotonin pathway) and nucleic acid metabolism.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40170-021-00249-6.

Heterogenous chemosensitivity of a panel of organoid lines derived from small cell neuroendocrine carcinoma of the uterine cervix

Small cell neuroendocrine carcinoma (SCNEC) of the uterine cervix is a rare disease with a poor prognosis. The lack of established disease models has hampered therapy development. We generated a panel of cancer tissue-originated spheroid (CTOS) lines derived from SCNEC of the uterine cervix using a method based upon cell-cell contact throughout the preparation and culturing processes. Using 11 CTOS lines, we assessed the sensitivity of various drugs used in clinical practice. Drug sensitivity assays revealed significant heterogeneous inter-CTOS chemosensitivity. Microarray analyses were then performed to identify sensitivity-related gene signatures. Specific gene sets were identified which likely contribute to the sensitivity to the tested drugs. We identified a line (Cerv54) that was exceptionally sensitive to irinotecan. Cerv54 had increased levels of CES1, which catalyzes the conversion of irinotecan to the active form, SN38, although in Cerv54 cells, SN38 was undetectable, CES1 expression and activity were markedly low compared to the liver, and a CES1 inhibitor had no effect on irinotecan sensitivity. These results suggested a novel irinotecan mode of action in Cerv54. Our CTOS lines may be useful for understanding the variation and mechanism of drug sensitivity, contributing to the understanding and development of chemotherapeutic drugs.

CALM1 promotes progression and dampens chemosensitivity to EGFR inhibitor in esophageal squamous cell carcinoma

Background

Calmodulin1 (CALM1) has been identified as one of the overexpression genes in a variety of cancers and EGFR inhibitor have been widely used in clinical treatment but it is unknown whether CALM1 and epidermal growth factor receptor (EGFR) have a synergistic effect in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to explore the synergistic effects of knock-out CALM1 combined with EGFR inhibitor (Afatinib) and to elucidate the role of CALM1 in sensitizing the resistance to Afatinib in ESCC.

Method

Immunohistochemistry (IHC) and qRT-PCR were used to examine the expression of CALM1 and EGFR in ESCC tissues. Kaplan–Meier survival analysis was used to analyze the clinical and prognostic significance of CALM1 and EGFR expression in ESCC. Furthermore, to evaluate the biological function of CALM1 in ESCC, the latest gene editing technique CRISPR/Cas9(Clustered regularly interspaced short palindromic repeats)was applied to knockout CALM1 in ESCC cell lines KYSE150, Eca109 and TE-1. MTT, flow cytometry, Transwell migration, scratch wound-healing and colony formation assays were performed to assay the combined effect of knock-out CALM1 and EGFR inhibitor on ESCC cell proliferation and migration. In addition, nude mice xenograft model was used to observe the synergistic inhibition of knock-out CALM1 and Afatinib.

Results

Both CALM1 and EGFR were found to be significantly over-expressed in ESCC compared with paired normal control. Over-expressed CALM1 and EGFR were significantly associated with clinical stage, T classification and poor overall prognosis, respectively. In vitro, the combined effect of knock-out CALM1 mediated by the lentivirus and EGFR inhibitor was shown to be capable of inhibiting the proliferation, inducing cell cycle arrest at G1/S stage and increasing apoptosis of KYSE-150 and Eca109 cells; invasion and migration were also suppressed. In vivo, the results of tumor weight and total fluorescence were markedly reduced compared with the sgCtrl-infected group and sgCAML1 group.

Conclusion

Our data demonstrated that knock-out of CALM1 could sensitize ESCC cells to EGFR inhibitor, and it may exert oncogenic role via promotion of EMT. Taken together, CALM1 may be a tempting target to overcome Afatinib resistance.

Impact of PIN1 Inhibition on Tumor Progression and Chemotherapy Sensitivity in Colorectal Cancer

BACKGROUND

Deregulated PIN1 is associated with cancer development and progression. Herein, for the first time, we evaluate the roles that PIN1 in tumorigenic characteristics of colorectal cancer (CRC) cells.

METHODS

In this study, PIN1 expression was knocked down in SW-48 cells by synthetic small interfering RNA (siRNA). After confirming the knockdown of PIN1, cell viability, colony formation, apoptosis, autophagy, cancer stem cell (CSC)-related genes, CSC-related signaling pathways, cell migration, and 5-FU chemosensitivity were evaluated in vitro.

RESULTS

Transfection of PIN1 siRNA into SW-48 cells inhibited cancer cell proliferation, migration, and increased apoptosis and autophagy. Transfected SW-48 cells had lower properties of CSCs through the inhibition of β-catenin and Notch1 gene expression. Moreover, inhibition of PIN1 enhanced the inhibitory effect of 5-FU on SW-48 cell proliferation.

CONCLUSION

Our results indicated that targeting of PIN1 serves as a promising therapeutic solution for the suppression of tumor progression processes in CRC.