FOXA1-induced circOSBPL10 potentiates cervical cancer cell proliferation and migration through miR-1179/UBE2Q1 axis

Dysregulation of the circ_0087502/miR-1179/TGFBR2 pathway supports gemcitabine resistance in pancreatic cancer

BACKGROUND

Circular RNAs (circRNAs) are a cohort of non-coding RNAs generated by back-splicing events. Accumulating evidence supports the crucial role of circRNAs in human tumorigenesis, metastasis, and chemoresistance. However, the role and mechanism of circRNA circ_0087502 in pancreatic cancer are yet unknown.

METHODS

The expression and function of circ_0087502 in pancreatic cancer were investigated using qRT-PCR and cell experiments. The predicted binding between circ_0087502 and microRNA-1179 (miR-1179), and between miR-1179 and TGFBR2, were examined using reporter assays.

RESULTS

Pancreatic cancer tissues and cell lines were discovered to express circ_0087502 at higher levels. Patients with pancreatic cancer who express circ_0087502 at high levels have a worse prognosis. In addition, circ_0087502 knockdown reduced the proliferation, migration, and invasion of pancreatic cancer cells and made them more sensitive to gemcitabine treatment. We found that circ_0087502 worked as a sponge for miR-1179, allowing miR-1179 to bind to the critical oncogene TGFBR2 in its 3'-untranslated region (3'-UTR). Pancreatic cancer cells were highly resistant to gemcitabine and had increased proliferation, migration, and invasion when miR-1179 was inhibited or overexpressed.

CONCLUSION

These results confirm that circ_0087502 activates the miR-1179/TGFBR2 axis to promote gemcitabine resistance in pancreatic cancer. Thus, our data might lay the groundwork for developing novel therapeutic strategies targeting circ_0087502 in pancreatic cancer patients.

Mosaic Chromosomal Alterations Are Associated With Increased Lung Cancer Risk: Insight From the INTEGRAL-ILCCO Cohort Analysis

INTRODUCTION

Mosaic chromosomal alterations (mCAs) detected in white blood cells represent a type of clonal hematopoiesis (CH) that is understudied compared with CH-related somatic mutations. A few recent studies indicated their potential link with nonhematological cancers, especially lung cancer.

METHODS

In this study, we investigated the association between mCAs and lung cancer using the high-density genotyping data from the OncoArray study of INTEGRAL-ILCCO, the largest single genetic study of lung cancer with 18,221 lung cancer cases and 14,825 cancer-free controls.

RESULTS

We identified a comprehensive list of autosomal mCAs, ChrX mCAs, and mosaic ChrY (mChrY) losses from these samples. Autosomal mCAs were detected in 4.3% of subjects, in addition to ChrX mCAs in 3.6% of females and mChrY losses in 9.6% of males. Multivariable logistic regression analysis indicated that the presence of autosomal mCAs in white blood cells was associated with an increased lung cancer risk after adjusting for key confounding factors, including age, sex, smoking status, and race. This association was mainly driven by a specific type of mCAs: copy-neutral loss of heterozygosity on autosomal chromosomes. The association between autosome copy-neutral loss of heterozygosity and increased risk of lung cancer was further confirmed in two major histologic subtypes, lung adenocarcinoma and squamous cell carcinoma. In addition, we observed a significant increase of ChrX mCAs and mChrY losses in smokers compared with nonsmokers and racial differences in certain types of mCA events.

CONCLUSIONS

Our study established a link between mCAs in white blood cells and increased risk of lung cancer.

Genetic diversity and functional implication of the long control region in human papillomavirus types 52, 58, and 16 from Central China

OBJECT

High-risk human papillomavirus (HR-HPV) is a main reason for cervical cancer. The long control region (LCR) of the genome plays a variety of roles in the transcription of the virus.

METHODS

LCR sequences were amplified by polymerase chain reaction (PCR) and confirmed by DNA sequencing. MEGA 11.0 software and NCBI blast were used to analyze the sequences and construct the Neighbor-Joining tree. In addition, the JASPAR database was used to predict the potential transcription factor binding sites (TFBS).

RESULTS

For HPV-52 LCR, 68 single nucleotide polymorphisms (SNPs), 8 deletions, and 1 insertion were found, 17 of which were novel variations. Most of the variants were clustered in B2 sub-lineage (96.22%). For HPV-58 LCR, 25.43% of samples were prototype. 49 SNPs, 2 deletions, and 1 insertion were observed in the remaining samples. A1 sub-lineage was the most frequent (64.16%). For HPV-16 LCR, 75 SNPs and 2 deletions were identified, 13 of which were newly identified. A total of 55.68% of the variants were distributed in A4 sub-lineage. The JASPAR results suggested that multiple variations occurred in TFBSs, which might affect the function of transcription factors.

CONCLUSIONS

This study provides experimental data for further studies on the epidemiology and biological function of LCR. Various LCR mutational data may prove useful for exploring the carcinogenic mechanism of HPV.

CMTM6 as a candidate risk gene for cervical cancer: Comprehensive bioinformatics study

Background: CKLF like MARVEL transmembrane domain containing 6 (CMTM6) is an important programmed cell death 1 ligand 1 regulator (PD-L1). CMTM6 was reported as an important regulator of PD-L1 by promoting PD-L1 expression in tumor cells against T cells. However, the function of CMTM6 in cervical cancer is not well characterized. In addition, the role of CMTM6 in the induction of epithelial-mesenchymal transition (EMT) in the context of cervical cancer is unknown. Methods: In this study, we evaluated the role of CMTM6, including gene expression analysis, miRNA target regulation, and methylation characteristic, using multiple bioinformatics tools based on The Cancer Genome Atlas (TCGA) database. The expression of CMTM6 in cervical cancer tissues and non-cancerous adjacent tissues was assessed using immunohistochemistry. In vitro and in vivo function experiments were performed to explore the effects of CMTM6 on growth and metastasis of cervical cancer. Results: Human cervical cancer tissues showed higher expression of CMTM6 than the adjacent non-cancerous tissues. In vitro assays showed that CMTM6 promoted cervical cancer cell invasion, migration, proliferation, and epithelial-mesenchymal transition via activation of mitogen-activated protein kinase (MAPK) c-jun N-terminal kinase (JNK)/p38 signaling pathway. We identified transcription factors (TFs), miRNAs, and immune cells that may interact with CMTM6. Conclusion: These results indicate that CMTM6 is a potential therapeutic target in the context of cervical cancer.

Circular RNAs as emerging players in cervical cancer tumorigenesis; A review to roles and biomarker potentials

Cervical cancer is the most lethal gynecological cancer among women worldwide. Most of the patients are diagnosed at the advanced stages due to late diagnosis and lack of accessible and valuable approaches for early detection of the disease. Circular RNAs (circRNAs) are a distinguishable class of non-coding RNAs with characteristic loop structures. Although their function has not been completely elucidated; however, recent evidence has suggested regulatory functions for circRNAs on gene expression controlling various biological functions like cell growth and apoptosis, development, embryogenesis, and pathogenesis of human diseases particularly cancers. Studies show the role of dysregulated circRNAs in biological processes including cell proliferation, migration, invasion, apoptosis, angiogenesis, and chemoresistance contributing to affect tumorigenesis in ovarian cancer cells, animal, and clinical studies. These effects can be defined as consistent with several tumorigenesis characteristics, which are defined as "hallmarks of cancer". Additionally, dysregulated circRNAs exhibit prognostic, and diagnostic potentials both in the prediction of prognosis in ovarian cancer patients, and also their discrimination from healthy individuals. Furthermore, targeting circRNAs has shown positive results in the suppression of malignant features of cancer cells, and also in overcoming chemoresistance. In this review, I have gathered the majority of studies evaluating the role of circRNAs in the development, and progression of cervical cancer, and also have discussed prognostic, diagnostic, and therapeutic potentials of circRNAs for clinical applications in cervical cancer patients.

FOXA1 Leads to Aberrant Expression of SIX4 Affecting Cervical Cancer Cell Growth and Chemoresistance

Cervical cancer (CC) is among the most prevalent cancers among female populations with high recurrence rates all over the world. Cisplatin (DDP) is the first-line treatment for multiple cancers, including CC. The main problem associated with its clinical application is drug resistance. This study is aimed at investigating the function and downstream regulation mechanism of forkhead-box A1 (FOXA1) in CC, which was verified as an oncogene in several cancers. Using GEO database and bioinformatics analysis, we identified FOXA1 as a possible oncogene in CC. Silencing of FOXA1 inhibited CC cell growth, invasion, and chemoresistance. Afterwards, the downstream gene of FOXA1 was predicted using a bioinformatics website and validated using ChIP and dual-luciferase assays. SIX4, a possible target of FOXA1, promoted CC cell malignant aggressiveness and chemoresistance. In addition, overexpression of SIX4 promoted phosphorylation of PI3K and AKT proteins and activated the PI3K/AKT signaling pathway. Further overexpression of SIX4 reversed the repressive effects of FOXA1 knockdown on CC cell growth, invasion, and chemoresistance in DDP-resistant cells. FOXA1-induced SIX4 facilitates CC progression and chemoresistance, highlighting a strong potential for FOXA1 to serve as a promising therapeutic target in CC.

Circ_0000263 facilitates the proliferation and inhibits the apoptosis of cervical cancer depending on the regulation of miR-1179/ABL2 axis

Circular RNA (circRNA) has been reported to participate in the progression of cervical cancer (CC). Studies on the role and mechanism of circ_0000263 in CC are limited, and more studies are needed. The expression of circ_0000263, microRNA (miR)-1179 and ABL proto-oncogene 2 (ABL2) mRNA in tissues and cells was analyzed by quantitative real-time PCR. The proliferation and apoptosis of CC cells were determined using cell counting kit 8 assay, Edu assay, colony formation assay and flow cytometry. The protein expression of proliferation markers, apoptosis markers and ABL2 was detected by western blot analysis. The interaction between RNAs was estimated via dual-luciferase reporter assay. Xenograft models were applied to explore the effect of circ_0000263 knockdown on CC tumorigenesis. Circ_0000263 was highly expressed in CC tumor tissues. Silencing of circ_0000263 suppressed CC cell proliferation and increased apoptosis. Circ_0000263 served as a sponge for miR-1179, and miR-1179 inhibitor reversed the regulation of si-circ_0000263 on CC cell proliferation and apoptosis. ABL2 could be targeted by miR-1179, and circ_0000263 could sponge miR-1179 to regulate ABL2. Overexpression of ABL2 reversed the anti-proliferation and pro-apoptosis roles of miR-1179 in CC cells. In addition, circ_0000263 knockdown reduced CC tumor growth by miR-1179/ABL2 axis. In brief, the results demonstrated that circ_0000263 exerted an oncogene role in CC, which suggested that circ_0000263 might be a promising therapeutic target for CC.

Non-coding RNAs as biomarkers for hepatocellular carcinoma-A systematic review

Hepatocellular carcinoma (HCC) is the sixth most common malignancy in the world and the fourth leading cause of cancer-related death, and its incidence is increasing globally. Despite significant advances in treatment strategies for HCC, the prognosis is still poor due to its high recurrence rate. Therefore, there is an urgent need to understand the pathogenesis of HCC and further develop new therapies to improve the prognosis and quality of life of HCC patients. MicroRNAs (miRNAs, miRs) are small non-coding RNAs involved in post-transcriptional regulation of gene expression that is abnormally expressed in cancer-associated genomic regions or vulnerable sites. More and more findings have shown that miRNAs are important regulatory factors of mRNA expression in HCC, and they are receiving more and more attention as a possible key biomarker of HCC. This review mainly summarizes the potential applied value on miRNAs as diagnostic, drug resistant, prognostic, and therapeutic biomarkers in the diagnosis, therapy, and prognosis of HCC. Also, we summarize the research value of long non-coding RNA (lncRNAs), circular RNAs (circRNAs), and miRNAs network in HCC as novel biomarkers, aiming at providing some references for the therapy of HCC.

circVAPA promotes the proliferation, migration and invasion of oral cancer cells through the miR-132/HOXA7 axis

Objective

To study the relationship between the circular RNA vesicle-associated membrane protein-associated protein A (circVAPA) and the pathogenesis of oral squamous cell carcinoma.

Methods

The expression of circVAPA was detected by RT-qPCR. In vitro loss-of-function experiments were performed in Cal-27 cells. The malignant phenotype of cells was evaluated by cell counting kit-8, clone formation and transwell assays. Luciferase reporter assays were used to assess the circVAPA/miR-132/homeobox A (HOXA) regulatory axis.

Results

circVAPA expression was significantly increased in oral cancer tissues and cells. The overall survival and progression-free survival of patients with oral cancer who exhibited high circVAPA expression were significantly shorter compared with those with low expression. circVAPA expression was closely related to tumor size, TNM stage and distant metastasis. circVAPA knockdown reduced the proliferation, invasion and migration of Cal-27 cells. MiR-132 was identified as a target of circVAPA in Cal-27 cells. Cotransfection with si-circVAPA and miR-132 inhibitor reversed the inhibitory effect of circVAPA knockdown on cell malignant phenotypes. HOXA7 was further identified as a downstream target of miR-132.

Conclusion

circVAPA is highly expressed in oral cancer, and its abnormal expression might affect the proliferation, invasion and migration of oral cancer cells by modulating the miR-132/HOXA7 signaling axis.

miR-338-3p inhibits autophagy in a rat model of allergic rhinitis after PM2.5 exposure through AKT/mTOR signaling by targeting UBE2Q1

Exposure to fine particulate matter (PM2.5) increases the incidence of allergic rhinitis (AR). microRNA (miRNA) can regulate cell proliferation, invasion and apoptosis. However, the mechanism of miR-338-3p in mediating PM2.5-induced autophagy in AR animal models remains unknown. To explore the mechanism of miR-338-3p in PM2.5-induced autophagy in AR, the human nasal epithelium cells and AR model exposed to PM2.5 were deployed. The results showed that miR-338-3p was down-regulated in both nasal mucosa of PM2.5-exacerbated AR rat models and PM2.5-treated RPMI-2650 cells. Forced expression of miR-338-3p could inhibit autophagy in vitro. miR-338-3p specifically bound to UBE2Q1 3'-untranslated region (3' UTR) and negatively regulated its expression. Overexpression of UBE2Q1 attenuated the inhibitory effects of miR-338-3p on PM2.5-induced autophagy of RPMI-2650 cells through AKT/mTOR pathway. Moreover, our in vivo study found that after administration of agomiR-338-3p in AR rats model, the expression of autophagy-related proteins decreased and nasal symptoms alleviated. In conclusion, this study revealed that miR-338-3p acts as an autophagy suppressor in PM2.5-exacerbated AR by directly targeting UBE2Q1 and affecting AKT/mTOR pathway.

The emerging roles of OSBP-related proteins in cancer: Impacts through phosphoinositide metabolism and protein-protein interactions

Oxysterol-binding protein -related proteins (ORPs) form a large family of intracellular lipid binding/transfer proteins. A number of ORPs are implicated in inter-organelle lipid transfer over membrane contacts sites, their mode of action involving in several cases the transfer of two lipids in opposite directions, termed countercurrent lipid transfer. A unifying feature appears to be the capacity to bind phosphatidylinositol polyphosphates (PIPs). These lipids are in some cases transported by ORPs from one organelle to another to drive the transfer of another lipid against its concentration gradient, while they in other cases may act as allosteric regulators of ORPs, or an ORP may introduce a PIP to an enzyme for catalysis. Dysregulation of several ORP family members is implicated in cancers, ORP3, -4, -5 and -8 being thus far the most studied examples. The most likely mechanisms underlying their associations with malignant growth are (i) impacts on PIP-mediated signaling events resulting in altered Ca²⁺ homeostasis, bioenergetics, cell survival, proliferation, and migration, (ii) protein-protein interactions affecting the activity of signaling factors, and (iii) modification of cellular lipid transport in a way that facilitates the proliferation of malignant cells. In this review I discuss the existing functional evidence for the involvement of ORPs in cancerous growth, discuss the findings in the light of the putative mechanisms outlined above and the possibility of employing ORPs as targets of anti-cancer therapy.

CircNEIL3 promotes cervical cancer cell proliferation by adsorbing miR-137 and upregulating KLF12

Background

CircRNAs play crucial roles in multiple tumours. However, the functions of most circRNAs in cervical cancer remain unclear.

Methods

This study collected GSE113696 data from the GEO database to search for differentially expressed circRNAs in cervical cancer. Quantitative reverse transcription PCR was used to detect the expression level of circNEIL3 in cervical cancer cells and tissues. Then, functional experiments in vitro and in vivo were performed to evaluate the effects of circNEIL3 in cervical cancer.

Results

CircNEIL3 was highly expressed in cervical cancer. In vivo and in vitro experiments verified that circNEIL3 enhanced the proliferation capacity of cervical cancer cells. RNA immunoprecipitation, luciferase reporter assay, pull-down assay, and fluorescent in situ hybridization confirmed the interaction between circNEIL3 and miR-137 in cervical cancer. A luciferase reporter assay showed that circNEIL3 adsorbed miR-137 and upregulated KLF12 to regulate the proliferation of cervical cancer cells.

Conclusions

CircNEIL3 is an oncogene in cervical cancer and might serve as a ceRNA that competitively binds to miR-137, thereby indirectly upregulating the expression of KLF12 and promoting the proliferation of cervical cancer cells.