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

Long non-coding RNA MIR600HG as a ceRNA inhibits the pancreatic cancer progression through regulating the miR-1197/PITPNM3 axis

Objective

Pancreatic cancer (PC) is considered to be a highly malignant cancer with poor prognosis. Long non-coding RNAs (lncRNAs) is the potential factor to predict cancer prognosis. The effect of MIR600HG in PC needs to be further studied. Our work mainly focused on the importance of MIR600HG for PC prognosis and its underlying molecular mechanism of regulating PC progression.

Methods

Data set was acquired from TCGA database to find differentially expressed genes and prognostic significance of MIR600HG in PC, and to construct the MIR600HG competitive endogenous RNA (ceRNA). Clinical specimens were collected to prove the analysis results. Vector over-expressed MIR600HG was transfected to study the roles of MIR600HG in proliferation, apoptosis, invasion and migration. The methods of CCK-8, flow cytometry, Transwell and scratch assays were all used in order to explore the apoptosis, migration and invasion. We evaluated the proliferation-related genes (PCNA, CyclinD1 and P27), as well as invasion and migration-related genes such as MMP-9, MMP-7 and ICAM-1. The transcriptional regulation between MIR600HG and miR-1197/PITPNM3 axis was determined with luciferase reporter assays.

Results

In present study, MIR600HG was dropped in both PC tissues and cells, and the down-regulated MIR600HG was closely related to the poor clinical outcomes in PC patients. MIR600HG could inhibit proliferation, migration and invasion in PC cells. We also investigated whether MIR600HG acting as a sponge of microRNA-1197 (miR-1197) and miR-1197 acting on PITPNM3. We found the positive association between MIR600HG and PITPNM3, as well as the negative association of miR-1197 and MIR600HG (or PITPNM3). Moreover, PITPNM3 mRNA and protein expression saw a simultaneous increase after the MIR600HG-overexpression (MIR600HG-OE), but this result partially diminished in MIR600HG-OE cells and miR-1197 mimics.

Conclusions

Our study explored the anticancer action of MIR600HG in PC by regulating miR-1197 to increase the expression of PITPNM3, which might help the diagnosis and therapy of PC.

Exosomal non-coding RNAs: Blueprint in colorectal cancer metastasis and therapeutic targets

Colorectal cancer (CRC) is ranked as the world's third-most prevalent cancer, and metastatic CRC considerably increases cancer-related fatalities globally. A number of complex mechanisms that are strictly controlled at the molecular level are involved in metastasis, which is the primary reason for death in people with CRC. Recently, it has become clear that exosomes, which are small extracellular vesicles released by non-tumorous and tumorigenic cells, play a critical role as communication mediators among tumor microenvironment (TME). To facilitate communication between the TME and cancer cells, non-coding RNAs (ncRNAs) play a crucial role and are recognized as potent regulators of gene expression and cellular processes, such as metastasis and drug resistance. NcRNAs are now recognized as potent regulators of gene expression and many hallmarks of cancer, including metastasis. Exosomal ncRNAs, like miRNAs, circRNAs, and lncRNAs, have been demonstrated to influence a number of cellular mechanisms that contribute to CRC metastasis. However, the molecular mechanisms that link exosomal ncRNAs with CRC metastasis are not well understood. This review highlights the essential roles that exosomal ncRNAs play in the progression of CRC metastatic disease and explores the therapeutic choices that are open to patients who have CRC metastases. However, exosomal ncRNA treatment strategy development is still in its early phases; consequently, additional investigation is required to improve delivery methods and find novel therapeutic targets as well as confirm the effectiveness and safety of these therapies in preclinical and clinical contexts.

Identification of MIR600HG/hsa-miR-342-3p/ANLN network as a potential prognosis biomarker associated with lmmune infiltrates in pancreatic cancer

Pancreatic cancer is one of the tumors with the worst prognosis, causing serious harm to human health. The RNA network and immune response play an important role in tumor progression. While a systematic RNA network linked to the tumor immune response remains to be further explored in pancreatic cancer. Based on The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, the MIR600HG/hsa-miR-342-3p/ANLN network was determined. WB and IHC were used to confirm the high expression of ANLN in pancreatic cancer. The prognostic model based on the RNA network could effectively predict the survival prognosis of patients. The analysis of immune infiltration showed that the MIR600HG/hsa-miR-342-3p/ANLN network altered the level of infiltration of T helper 2 (Th2) and effector memory T (Tem) cells. Furthermore, we found that the chemokines chemokine ligand (CCL) 5 and CCL14 may play a key role in immune cell infiltration mediated by the RNA network. In conclusion, this study constructed a prognostic model based on the MIR600HG/hsa-miR-342-3p/ANLN network and found that it may function in tumor immunity.

Identification and validation of m5c-related lncRNA risk model for ovarian cancer

Ovarian cancer (OC) is one of the common malignant tumors that seriously threaten women's health, and there is a lack of clinical prognostic predictors, while m5c and lncRNA have been shown to be predictive of multiple cancers, including OC. Therefore, our goal was to construct a risk model for OC based on m5c-related lncRNA.340 m5c-related lncRNA were identified and a novel risk model of OC ground on nine m5C-related lncRNA was constructed using LASSO-COX regression analysis. Kaplan-Meier analysis showed there was a significant difference in prognosis between risk groups. We established a nomogram which was a good predictor of overall survival. In addition, GSEA was enriched in multiple pathways and immune function analysis suggested that immune infiltration varies depending on the risk group. In vitro experiments show that AC005562.1, a key lncRNA of the risk model, is highly expressed in OC cells and promotes OC cell proliferation. Finally, we further explored the potential biological markers of m5c-related lncRNA in OC with WGCNA analysis and established a ceRNA network. In conclusion,we have developed a reliable m5c-related prediction model and performed systematic validation and exploration of various aspects. These results can be used for the assessment of OC prognosis and the discovery of novel biomarkers.

Identification of immune and Toll-like receptor signaling pathway related feature lncRNAs to construct diagnostic nomograms for acute ischemic stroke

We aimed to identify the immune and Toll-like receptor (TLR) signaling pathway related feature lncRNAs to construct the diagnostic nomograms for acute ischemic stroke (AIS). Two AIS-associated expression profiles GSE16561 and GSE22255 were downloaded from NCBI Gene Expression Omnibus, the former was the training set and the latter was the validation set. The differential expression genes (DEGs) and lncRNAs (DElncRNAs) related to TLR signaling pathway were identified between AIS and control groups. The single sample gene set enrichment analysis (ssGSEA) was applied to evaluate the immune infiltration. The immune and TLR signaling pathway related DElncRNAs were determined. Three optimization algorithms were utilized to select the immune and TLR signaling pathway related feature lncRNAs to construct the diagnostic nomograms of AIS. Based on the lncRNA signature, a ceRNA network was constructed. 37 DEGs and 28 DElncRNAs related to TLR signaling pathway were identified in GSE16561. 16 immune cell types exhibited significant differences in distribution between AIS and control groups. 28 immune and TLR signaling pathway related DElncRNAs were determined. 8 immune and TLR signaling pathway related feature lncRNAs were selected. The diagnostic nomograms of AIS performed well in both datasets. A ceRNA network was constructed consisting of 7 immune and TLR signaling pathway related feature lncRNAs as well as 19 AIS related miRNAs and 21 TLR signaling pathway related genes. LINC00173, LINC01089, LINC02210, MIR600HG, SNHG14, TP73-AS1, LINC00680 and CASC2 may be the potential biomarkers of AIS diagnosis, and TLR signaling pathway may be a promising immune related therapeutic target for AIS.

Novel strategies to reverse chemoresistance in colorectal cancer

Colorectal cancer (CRC) is a common gastrointestinal malignancy with high morbidity and fatality. Chemotherapy, as traditional therapy for CRC, has exerted well antitumor effect and greatly improved the survival of CRC patients. Nevertheless, chemoresistance is one of the major problems during chemotherapy for CRC and significantly limits the efficacy of the treatment and influences the prognosis of patients. To overcome chemoresistance in CRC, many strategies are being investigated. Here, we review the common and novel measures to combat the resistance, including drug repurposing (nonsteroidal anti-inflammatory drugs, metformin, dichloroacetate, enalapril, ivermectin, bazedoxifene, melatonin, and S-adenosylmethionine), gene therapy (ribozymes, RNAi, CRISPR/Cas9, epigenetic therapy, antisense oligonucleotides, and noncoding RNAs), protein inhibitor (EFGR inhibitor, S1PR2 inhibitor, and DNA methyltransferase inhibitor), natural herbal compounds (polyphenols, terpenoids, quinones, alkaloids, and sterols), new drug delivery system (nanocarriers, liposomes, exosomes, and hydrogels), and combination therapy. These common or novel strategies for the reversal of chemoresistance promise to improve the treatment of CRC.

The Expanding Role of Cancer Stem Cell Marker ALDH1A3 in Cancer and Beyond

Aldehyde dehydrogenase 1A3 (ALDH1A3) is one of 19 ALDH enzymes expressed in humans, and it is critical in the production of hormone receptor ligand retinoic acid (RA). We review the role of ALDH1A3 in normal physiology, its identification as a cancer stem cell marker, and its modes of action in cancer and other diseases. ALDH1A3 is often over-expressed in cancer and promotes tumor growth, metastasis, and chemoresistance by altering gene expression, cell signaling pathways, and glycometabolism. The increased levels of ALDH1A3 in cancer occur due to genetic amplification, epigenetic modifications, post-transcriptional regulation, and post-translational modification. Finally, we review the potential of targeting ALDH1A3, with both general ALDH inhibitors and small molecules specifically designed to inhibit ALDH1A3 activity.

Long Noncoding RNA MIR600HG Binds to MicroRNA-125a-5p to Prevent Pancreatic Cancer Progression Via Mitochondrial Tumor Suppressor 1-Dependent Suppression of Extracellular Regulated Protein Kinases Signaling Pathway

OBJECTIVES

Significance of long noncoding RNAs in pancreatic cancer (PC) progression has been documented. Here, we identified a novel long noncoding RNA MIR600HG in PC and its underlying mechanism during PC progression.

METHODS

Through bioinformatics analysis, we selected MIR600HG, microRNA-125a-5p (miR-125a-5p), and mitochondrial tumor suppressor 1 (MTUS1) as objects with their expression patterns assayed in the collected PC tissues and PC cells. Pancreatic cancer cells were manipulated with ectopic expression and deficiency of MIR600HG, miR-125a-5p, and/or MTUS1 for assaying cell biological processes in vitro and tumorigenesis in vivo.

RESULTS

MIR600HG and MTUS1 levels were downregulated and miR-125a-5p was upregulated in PC tissues and cells. MIR600HG could bind to miR-125a-5p, while miR-125a-5p negatively targeted MTUS1. MIR600HG resulted in suppression in malignant properties of PCs. All these changes could be reversed by miR-125a-5p elevation. In addition, miR-125a-5p targeted MTUS1 to activate the extracellular regulated protein kinases signaling pathway. In vivo experiment also verified the inhibitory role of MIR600HG in PC.

CONCLUSIONS

Taken together, MIR600HG acts as an inhibitor for PC progression by upregulating miR-125a-5p-mediated MTUS1 through extracellular regulated protein kinases pathway.

Identification of a lncRNA based signature for pancreatic cancer survival to predict immune landscape and potential therapeutic drugs

Pancreatic cancer is one major digestive malignancy with a poor prognosis. Given the clinical importance of lncRNAs, developing a novel molecular panel with lncRNAs for pancreatic cancer has great potential. As a result, an 8-lncRNA-based robust prognostic signature was constructed using a random survival forest model after examing the expression profile and prognostic significance of lncRNAs in the PAAD cohort from TCGA. The efficacy and effectiveness of the lncRNA-based signature were thoroughly assessed. Patients with high- and low-risk defined by the signature underwent significantly distinct OS expectancy. Most crucially the training group’s AUCs of ROC approached 0.90 and the testing group similarly had the AUCs above 0.86. The lncRNA-based signature was shown to behave as a prognostic indicator of pancreatic cancer, either alone or simultaneously with other factors, after combined analysis with other clinical-pathological factors in Cox regression and nomogram. Additionally, using GSEA and CIBERSORT scoring methods, the immune landscape and variations in biological processes between high- and low-risk subgroups were investigated. Last but not least, drug databases were searched for prospective therapeutic molecules targeting high-risk patients. The most promising compound were Afatinib, LY-303511, and RO-90-7501 as a result. In conclusion, we developed a novel lncRNA based prognostic signature with high efficacy to stratify high-risk pancreatic cancer patients and screened prospective responsive drugs for targeting strategy.

Downregulated Reprimo by LINC00467 participates in the growth and metastasis of gastric cancer

Gastric cancer (GC) as an aggressive malignancy still causes a global health problem. It has been documented that long noncoding RNAs are involved in GC development. Therefore, this research was designed to explore the role of LINC00467 in the growth and metastasis of GC. The expression of LINC00467 and Reprimo in GC tissues and cells was detected. The binding relationship among LINC00467, DNA methyltransferase 1 (DNMT1) and Reprimo was assessed following. Reprimo promoter methylation was detected by methylation sequencing. GC cell lines overexpressing or knock downing LINC00467 were constructed for pinpointing the effect of LINC00467 on cell functions as well as growth and metastasis of GC cells in vivo. LINC00467 was highly expressed, whereas Reprimo was poorly expressed in GC tissues and cells. Mechanically, LINC00467 promoted the methylation and decreased the expression of Reprimo promoter by recruiting DNMT1 in GC cells. Knockdown of LINC00467 diminished the malignant properties of GC cells. Knockdown of LINC00467 reduced tumorigenesis and metastasis of GC cells in vivo. LINC00467 might exert oncogenic effects in GC via Reprimo downregulation by recruiting DNMT1.

MIR600HG sponges miR-125a-5p to regulate glycometabolism and cisplatin resistance of oral squamous cell carcinoma cells via mediating RNF44

There is increasing evidence that dysregulated long non-coding RNA (lncRNA) is implicated in tumorigenesis and progression. We aim to explore the role of lncRNA MIR600HG in glycometabolism and cisplatin (DDP) resistance of oral squamous cell carcinoma (OSCC) cells via regulating microRNA-125a-5p (miR-125a-5p) and RING finger 44 (RNF44). Expression of MIR600HG, miR-125a-5p, and RNF44 in OSCC clinical samples, cell lines, and DDP-resistant OSCC cells (SCC-9/DDP) was determined. In SCC-9 cells, proliferation, IC50 value of DDP, migration, invasion, and apoptosis were detected; in SCC-9/DDP cells, proliferation, IC50 value of DDP, apoptosis, glucose consumption, and production of lactic acid and ATP were evaluated. The interaction of MR600HG, miR-125a-5p, and RNF44 was verified. MIR600HG and RNF44 were upregulated while miR-125a-5p was downregulated in OSCC tissues and cell lines, and also in SCC-9/DDP cells. In SCC-9 cells, MIR600HG overexpression improved cell growth, metastasis, and inhibited cell susceptibility to DDP; in SCC-9/DDP cells, silencing of MIR600HG promoted apoptosis, improved DDP sensitivity, and inhibited cell glycolysis. Downregulation of miR-125a-5p showed the opposite effect to downregulation of MIR600HG. MIR600HG bound to miR-125a-5p and miR-125a-5p targeted RNF44. Downregulation of miR-125a-5p reversed the improvement of DDP sensitivity and the inhibition of cell glycolysis by downregulated MIR600HG on SCC-9/DDP cells. Downregulating RNF44 reversed the promotion of DDP resistance and cell glycolysis of SCC-9/DDP cells mediated by downregulation of miR-125a-5p. Collectively, our study addresses that MIR600HG downregulation elevates miR-125a-5p and reduces RNF44 expression, thereby improving DDP sensitivity and inhibiting glycolysis in DDP-resistant OSCC cells.

Derivation, Comprehensive Analysis, and Assay Validation of a Pyroptosis-Related lncRNA Prognostic Signature in Patients With Ovarian Cancer

Background

Pyroptosis is regulated by long non-coding RNAs (lncRNAs) in ovarian cancer (OC). Therefore, a comprehensive analysis of pyroptosis-related lncRNAs (PRLs) in OC is crucial for developing therapeutic strategies and survival prediction.

Methods

Based on public database raw data, mutations in the landscape of pyroptosis-related genes (PRGs) in patients with OC were investigated thoroughly. PRLs were identified by calculating Pearson correlation coefficients. Cox and LASSO regression analyses were performed on PRLs to screen for lncRNAs participating in the risk signature. Furthermore, receiver operating characteristic (ROC) curves, Kaplan-Meier survival analyses, decision curve analysis (DCA) curves, and calibration curves were used to confirm the clinical benefits. To assess the ability of the risk signature to independently predict prognosis, it was included in a Cox regression analysis with clinicopathological parameters. Two nomograms were constructed to facilitate clinical application. In addition, potential biological functions of the risk signature were investigated using gene function annotation. Subsequently, immune-related landscapes and BRCA1/2 mutations were compared in different risk groups using diverse bioinformatics algorithms. Finally, we conducted a meta-analysis and in-vitro assays on alternative lncRNAs.

Results

A total of 374 patients with OC were randomized into training and validation cohorts (7:3). A total of 250 PRLs were selected from all the lncRNAs. Subsequently, a risk signature (DICER1-AS1, MIR600HG, AC083880.1, AC109322.1, AC007991.4, IL6R-AS1, AL365361.1, and AC022098.2) was constructed to distinguish the risk of patient survival. The ROC curve, K-M analysis, DCA curve, and calibration curve indicated excellent predictive performance for determining overall survival (OS) based on the risk signature in each cohort (p < 0.05). The Cox regression analysis indicated that the risk signature was an independent prognostic factor for OS (p < 0.05). Moreover, significant differences in the immune response and BRCA1 mutations were identified in different groups distinguished by the risk signature (p < 0.05). Interestingly, in-vitro assays showed that an alternative lncRNA (DICER1-AS1) could promote OC cell proliferation.

Conclusion

The PRL risk signature could independently predict overall survival and guide treatment in patients with OC.

LncRNAs, the Molecules Involved in Communications With Colorectal Cancer Stem Cells

Colorectal cancer stem cells (CRCSCs) can actively self-renew, as well as having multidirectional differentiation and tumor regeneration abilities. Because the high functional activities of CRCSCs are associated with low cure rates in patients with colorectal cancer, efforts have sought to determine the function and regulatory mechanisms of CRCSCs. To date, however, the potential regulatory mechanisms of CRCSCs remain incompletely understood. Many non-coding genes are involved in tumor invasion and spread through their regulation of CRCSCs, with long non-coding RNAs (lncRNAs) being important non-coding RNAs. LncRNAs may be involved in the colorectal cancer development and drug resistance through their regulation of CRCSCs. This review systematically evaluates the latest research on the ability of lncRNAs to regulate CRCSC signaling pathways and the involvement of these lncRNAs in colorectal cancer promotion and suppression. The regulatory network of lncRNAs in the CRCSC signaling pathway has been determined. Further analysis of the potential clinical applications of lncRNAs as novel clinical diagnostic and prognostic biomarkers and therapeutic targets for colorectal cancer may provide new ideas and protocols for the prevention and treatment of colorectal cancer.

lncRNA MIR600HG Knockdown Alleviates Cognitive Impairment in Alzheimer's Disease Through NEDD4L Mediated PINK1 Degradation

BACKGROUND

Growing evidence has demonstrated that long non-coding RNAs (lncRNAs) play a critical role in Alzheimer's disease (AD), which is characterized by sustained mitochondrial dysfunction, inevitable memory loss, and cognitive decline. However, the potential function of lncRNAs MIR600 Host Gene (MIR600HG) in AD remains unanswered.

OBJECTIVE

Our study aimed to investigate the role of MIR600HG and its related molecular mechanism in AD.

METHODS

The expression of MIR600HG was examined by qRT-PCR. The MIR600HG interacting proteins were identified by RNA pull-down assay and mass spectrometry and verified by RNA immunoprecipitation. Immunofluorescence staining was applied to examine the colocalization of PINK1 and NEDD4L. The PINK1 level and the activation of autophagy were detected by immunoblotting. Morris water maze test was performed to evaluate cognitive decline in AD mice model.

RESULTS

MIR600HG expression was elevated during aging in two different types of AD transgenic mouse models. Next, we found that increased MIR600HG directly interact with NEDD4L, which promoted PINK1 ubiquitination and degradation, and as well as autophagy activation. Additionally, MIR600HG promoted Aβ production and suppressed Cytochrome C Oxidase activity. Administration of AAV-shMIR600HG restored the Cytochrome C Oxidase activity and inhibited Aβ production. Furthermore, PINK1 overexpression or MIR600HG knockdown significantly ameliorated the cognitive impairment in APP/PS1 mice. PINK1 depletion recovered the spatial memory defect in the AAV-shMIR600HG injected APP/PS1 mice.

CONCLUSION

MIR600HG was increased in AD and promoted AD pathogenesis. Targeting MIR600HG significantly improved cognitive function in AD mice, which could pave the way for exciting new avenues in AD therapeutic strategy research.

Construction of a ceRNA Network and Analysis of Tumor Immune Infiltration in Pancreatic Adenocarcinoma

Pancreatic adenocarcinoma (PAAD) is characterized by high malignancy, frequent metastasis, and recurrence with an unfavorable prognosis. This study is aimed at constructing a prognostic model for tumor-infiltrating immune cells and a competing endogenous RNA (ceRNA) network in PAAD and analyzing susceptibilities of chemotherapy and immunotherapy of PAAD. Gene expression profiles and clinical information of PAAD were downloaded from The Cancer Genome Atlas (TCGA) database and divided into the tumor group and the normal group. A total of five PAAD survival-related key genes in the ceRNA network and three survival-related immune infiltrating cells were uncovered, and two survival risk models and nomograms were constructed. The efficiency and performance of the two models were verified using multi-index area under the curve analysis at different time points, decision curve analysis, and calibration curves. Co-expression analysis showed that LRRC1, MIR600HG, and RNF166 in the ceRNA network and tumor-infiltrating immune cells including CD8 T cells and M1 macrophages were likely related to the PAAD prognosis, and the expression of key ceRNA-related genes was experimently validated in tissues and cell lines by RT-qPCR. Patients with low risk scores for key genes in the ceRNA network displayed a positive response to anti-programmed death-1 (PD-1) treatment and greater sensitivity to chemotherapeutic drugs such as docetaxel, lapatinib, and paclitaxel. More importantly, our results suggested that the IC50 values of gemcitabine in PAAD were not significantly different between the high and low risk groups. The expression levels of immune checkpoints were significantly different in the high-risk and low-risk groups. The prognostic model, nomogram, and drug analysis may provide an essential reference for PAAD patient management in the clinic.

Identification and Roles of miR-29b-1-3p and miR29a-3p-Regulated and Non-Regulated lncRNAs in Endocrine-Sensitive and Resistant Breast Cancer Cells

Despite improvements in the treatment of endocrine-resistant metastatic disease using combination therapies in patients with estrogen receptor α (ERα) primary tumors, the mechanisms underlying endocrine resistance remain to be elucidated. Non-coding RNAs (ncRNAs), including microRNAs (miRNA) and long non-coding RNAs (lncRNA), are targets and regulators of cell signaling pathways and their exosomal transport may contribute to metastasis. Previous studies have shown that a low expression of miR-29a-3p and miR-29b-3p is associated with lower overall breast cancer survival before 150 mos. Transient, modest overexpression of miR-29b1-3p or miR-29a-3p inhibited MCF-7 tamoxifen-sensitive and LCC9 tamoxifen-resistant cell proliferation. Here, we identify miR-29b-1/a-regulated and non-regulated differentially expressed lncRNAs in MCF-7 and LCC9 cells using next-generation RNA seq. More lncRNAs were miR-29b-1/a-regulated in LCC9 cells than in MCF-7 cells, including DANCR, GAS5, DSCAM-AS1, SNHG5, and CRND. We examined the roles of miR-29-regulated and differentially expressed lncRNAs in endocrine-resistant breast cancer, including putative and proven targets and expression patterns in survival analysis using the KM Plotter and TCGA databases. This study provides new insights into lncRNAs in endocrine-resistant breast cancer.

The Emerging Landscape of Long Non-Coding RNAs in Colorectal Cancer Metastasis

Colorectal cancer (CRC) is one of the most common gastrointestinal cancers, with extremely high rates of morbidity and mortality. The main cause of death in CRC is distant metastasis; it affects patient prognosis and survival and is one of the key challenges in the treatment of CRC. Long non-coding RNAs (lncRNAs) are a group of non-coding RNA molecules with more than 200 nucleotides. Abnormal lncRNA expression is closely related to the occurrence and progression of several diseases, including cancer. Recent studies have shown that numerous lncRNAs play pivotal roles in the CRC metastasis, and reversing the expression of these lncRNAs through artificial means can reduce the malignant phenotype of metastatic CRC to some extent. This review summarizes the major mechanisms of lncRNAs in CRC metastasis and proposes lncRNAs as potential therapeutic targets for CRC and molecular markers for early diagnosis.

Forkhead-box A3 (FOXA3) represses cancer stemness and partially potentiates chemosensitivity by targeting metastasis-associated in colon cancer 1 (MACC1) signaling pathway in colorectal cancer cells

BACKGROUND

The major challenge to the treatment of advanced colorectal cancer (CRC) is persistent occurrence of chemoresistance. One of the established etiologies is the existence of cancerstem-like cells (CSCs) using which tumors resist to external therapeutic challenges.

OBJECTIVE

The forkhead-box A3 (FOXA3) is a potent transcription factor that potentiates the acquisition and maintenance of stemness fate in many physiological systems. However, its effect on cancer stemness, particularly treatment, has not been explored in CRC, forming the basis of the current study.

METHODS

FOXA3 expression in oxaliplatin-resistant CRC tissues and cells was evaluated using RT-qPCR. Effects of FOXA3 manipulation on sensitivity to oxaliplatin were assessed using WST-1, apoptotic ELISA, colony formation and xenograft model. Effects of FOXA3 alteration on CSCs were determined using tumor sphere assay and CD44 staining. Transcriptional regulation of MACC1 by FOXA3 was studied using ChIP, Co-IP and luciferase reporter assay.

RESULTS

FOXA3 expression was significantly reduced in tumor samples from oxaliplatin-non-responsive patients compared with that in tumor samples from oxaliplatin-sensitive patients. This downregulation of FOXA3 expression predicted a poor post-chemotherapy overall- or disease-free survival in our 117-patient cohort. FOXA3 down-regulation significantly enhanced cell survival and stem-like properties, thus rendering the CRC cells unresponsiveness to oxaliplatin-induced cell death. Mechanistically, the anti-neoplasic effect of FOXA3 was mediated mainly through transcriptional repression of metastasis-associated in colon cancer 1 (MACC1) in oxaliplatin-resistant CRC cells.

CONCLUSION

Our findings establish FOXA3 as a potent tumor suppressor in CRC, which may disrupt the maintenance of stemness and modulate sensitivity to oxaliplatin by inhibiting the transcription of MACC1 within CRC cells.

The predominant expression of cancer stem cell marker ALDH1A3 in tumor infiltrative area is associated with shorter overall survival of human glioblastoma

Background

ALDH1A3 is a cancer stem cell marker in neoplasms including glioblastoma (GBM). However, the comprehensive role of ALDH1A3 in GBM remains unclear. This study attempted to investigate the expression of ALDH1A3 in human GBM tissues and its association with clinical parameters.

Methods

Thirty primary GBM and 9 control were enrolled in this study. ALDH1A3 mRNA and protein expression levels were detected by RT²-PCR and western blot, respectively. Immunohistochemistry and immunofluorescence staining were performed to evaluate the regional and cellular expression manner of ALDH1A3. The association of ALDH1A3 expression with multiple clinical parameters was analyzed.

Results

ALDH1A3 protein level, but not mRNA level, in a subgroup of GBM was significantly higher than that in the control group. ALDH1A3 immunoreactivity was detected heterogeneously in individual GBMs. Fifteen of 30 cases showed a positive of ALDH1A3 immunoreactivity which was predominantly observed in the tumor infiltrative area (TI). Double immunofluorescence staining revealed a co-localization of ALDH1A3 with GFAP in glial-shaped cells and in tumor cells. ALDH1A3 immunoreactivity was often merged with CD44, but not with CD68. Moreover, ALDH1A3 expression was positively associated with the tumor edema grade and inversely with overall survival (OS) (median OS: 16 months vs 10 months), but with neither MGMT promoter methylation status nor Ki67 index in GBM. An upregulation of ALDH1A3 was accompanied by a reduced expression of STAT3β and p-STAT3β.

Conclusions

Inter- and intra-tumoral heterogeneous expression of ALDH1A3 was exhibited in GBMs. A high immunoreactivity of ALDH1A3 in tumor infiltrative area was associated with shorter OS, especially in patients with MGMT promoter methylation. Our findings propose ALDH1A3 not only as a predictive biomarker but also as a potential target for personalized therapy of GBM.