Chemo-resistance of A172 glioblastoma cells is controlled by miR-1271-regulated Bcl-2

MicroRNAs in adult high-grade gliomas: Mechanisms of chemotherapeutic resistance and their clinical relevance

Notorious for its high mortality rate, the current standard treatment for high-grade gliomas remains a challenge. This is largely due to the complex heterogeneity of the tumour coupled with dysregulated molecular mechanisms leading to the development of drug resistance. In recent years, microRNAs (miRNAs) have been considered to provide important information about the pathogenesis and prognostication of gliomas. miRNAs have been shown to play a specific role in promoting oncogenesis and regulating resistance to anti-glioma therapeutic agents through diverse cellular mechanisms. These include regulation of apoptosis, alterations in drug efflux pathways, enhanced activation of oncogenic signalling pathways, Epithelial-Mesenchymal Transition-like process (EMT-like) and a few others. With this knowledge, upregulation or inhibition of selected miRNAs can be used to directly affect drug resistance in glioma cells. Moreover, the clinical use of miRNAs in glioma management is becoming increasingly valuable. This comprehensive review delves into the role of miRNAs in drug resistance in high-grade gliomas and underscores their clinical significance. Our analysis has identified a distinct cluster of oncogenic miRNAs (miR-9, miR-21, miR-26a, miR-125b, and miR-221/222) and tumour suppressive miRNAs (miR-29, miR-23, miR-34a-5p, miR 181b-5p, miR-16-5p, and miR-20a) that consistently emerge as key players in regulating drug resistance across various studies. These miRNAs have demonstrated significant clinical relevance in the context of resistance to anti-glioma therapies. Additionally, the clinical significance of miRNA analysis is emphasised, including their potential to serve as clinical biomarkers for diagnosing, staging, evaluating prognosis, and assessing treatment response in gliomas.

MicroRNA and mRNA Expression Changes in Glioblastoma Cells Cultivated under Conditions of Neurosphere Formation

Glioblastoma multiforme (GBM) is one of the most highly metastatic cancers. The study of the pathogenesis of GBM, as well as the development of targeted oncolytic drugs, require the use of actual cell models, in particular, the use of 3D cultures or neurospheres (NS). During the formation of NS, the adaptive molecular landscape of the transcriptome, which includes various regulatory RNAs, changes. The aim of this study was to reveal changes in the expression of microRNAs (miRNAs) and their target mRNAs in GBM cells under conditions of NS formation. Neurospheres were obtained from both immortalized U87 MG and patient-derived BR3 GBM cell cultures. Next generation sequencing analysis of small and long RNAs of adherent and NS cultures of GBM cells was carried out. It was found that the formation of NS proceeds with an increase in the level of seven and a decrease in the level of 11 miRNAs common to U87 MG and BR3, as well as an increase in the level of 38 and a decrease in the level of 12 mRNA/lncRNA. Upregulation of miRNAs hsa-miR: -139-5p; -148a-3p; -192-5p; -218-5p; -34a-5p; and -381-3p are accompanied by decreased levels of their target mRNAs: RTN4, FLNA, SH3BP4, DNPEP, ETS2, MICALL1, and GREM1. Downregulation of hsa-miR: -130b-5p, -25-5p, -335-3p and -339-5p occurs with increased levels of mRNA-targets BDKRB2, SPRY4, ERRFI1 and TGM2. The involvement of SPRY4, ERRFI1, and MICALL1 mRNAs in the regulation of EGFR/FGFR signaling highlights the role of hsa-miR: -130b-5p, -25-5p, -335-3p, and -34a-5p not only in the formation of NS, but also in the regulation of malignant growth and invasion of GBM. Our data provide the basis for the development of new approaches to the diagnosis and treatment of GBM.

Identification of Prognostic LncRNAs Subtypes Predicts Prognosis and Immune Microenvironment for Glioma

Glioma is the most commonly occurring primary neuroepithelial neoplasm. Long noncoding RNAs (lncRNAs) are emerging as pivotal modulators of gene expression in the immune system and play critical roles in the growth, progression, and immune response of carcinomas. In this study, we performed univariate Cox regression analysis on survival data from TCGA and identified 20 prognostic lncRNAs. Moreover, we revealed that these prognosis-related lncRNAs (PRLnc) were dysregulated in glioma. Furthermore, we constructed a signature based on the expression levels of these prognosis-related lncRNAs based on 13 prognostic lncRNAs, including AGAP2-AS1, CYTOR, MIR155HG, LINC00634, HOTAIRM1, SNHG18, LINC01841, LINC01842, LINC01426, MIR9-3HG, TMEM220-AS1, LINC00641, LINC01270, and LINC01503. The Kaplan–Meier curves show that high-risk patients had a shorter survival time. Finally, the glioma samples were classified into 2 subgroups based on the median expression of prognosis-related lncRNAs in each sample. In summary, these findings suggest that PRLnc is associated with tumor-infiltrating immune cells in glioma and that subtype 2 patients may respond more positively to immunotherapy.

MicroRNAs, Key Regulators in Glioma Progression as Potential Therapeutic Targets for Chinese Medicine

Gliomas are tumors of the primary central nervous system associated with poor prognosis and high mortality. The 5-year survival rate of patients with gliomas received surgery combined with chemotherapy or radiotherapy does not exceed 5%. Although temozolomide is commonly used in the treatment of gliomas, the development of resistance limits its use. MicroRNAs are non-coding RNAs involved in numerous processes of glioma cells, such as proliferation, migration and apoptosis. MicroRNAs regulate cell cycle, PI3K/AKT signal pathway, and target apoptosis-related genes (e.g., BCL6), angiogenesis-related genes (e.g., VEGF) and other related genes to suppress gliomas. Evidence illustrates that microRNAs can regulate the sensitivity of gliomas to temozolomide, cisplatin, and carmustine, thereby enhancing the efficacy of these agents. Moreover, traditional Chinese medicine (e.g., tanshinone IIA, xanthohumol, and curcumin) exert antiglioma effects by regulating the expression of microRNAs, and then microRNAs inhibit gliomas through influencing the process of tumors by targeting certain genes. In this paper, the mechanisms through which microRNAs regulate the sensitivity of gliomas to therapeutic drugs are described, and traditional Chinese medicine that can suppress gliomas through microRNAs are discussed. This review aims to provide new insights into the traditional Chinese medicine treatment of gliomas.

Low-Dose Apatinib Improves the Prognosis of Patients with Recurrent High-Grade Gliomas

Objective. To evaluate the efficacy, safety, and prognostic value of low-dose apatinib in combination with temozolomide in the treatment of primary or recurrent high-grade gliomas (HGGs). Methods. A retrospective analysis of patients with postoperative and recurrent HGGs treated in our hospital from April 1, 2018, to April 30, 2020. Patients should be treated by combination therapy (surgery + radiotherapy + chemotherapy). Patients who received apatinib combined with temozolomide chemotherapy were allocated to the research group (RG), while patients who received temozolomide chemotherapy alone were allocated to the control group (CG). The efficacy and toxic side effects were compared between the two groups. Results. There were 67 qualified patients retrieved, including 37 cases in the RG and 30 cases in the CG. There were no significant differences in objective remission rate (ORR) or disease control rate (DCR) between the control group and the study group ( $P>0.05$ ). However, the overall improvement of clinical efficacy in the observation group was better than that in the control group ( $P<0.05$ ). There was no significant difference in the incidence of adverse effects between the two groups ( $P>0.05$ ). There were no significant differences in overall survival (OS) or progression-free survival (PFS) between the two groups ( $P>0.05$ ). Conclusion. Low-dose apatinib combined with temozolomide and radiotherapy for HGGs is effective in improving efficacy, relieving brain edema, reducing the use of glucocorticoid drugs, and improving patients’ quality of life. It has mild adverse effects and is well tolerated by patients.

Cancer drug resistance related microRNAs: recent advances in detection methods

MiRNAs are related to cancer drug resistance through various mechanisms. The advanced detection methods for the miRNAs are reviewed.

Molecular Mechanisms of Drug Resistance in Glioblastoma

Glioblastoma multiforme (GBM) is the most common and fatal primary brain tumor, is highly resistant to conventional radiation and chemotherapy, and is not amenable to effective surgical resection. The present review summarizes recent advances in our understanding of the molecular mechanisms of therapeutic resistance of GBM to already known drugs, the molecular characteristics of glioblastoma cells, and the barriers in the brain that underlie drug resistance. We also discuss the progress that has been made in the development of new targeted drugs for glioblastoma, as well as advances in drug delivery across the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB).

Molecular Mechanisms of miR-1271 Dysregulation in Human Cancer

MicroRNA is a small noncoding RNA that plays a role in regulating gene expression. miR-1271 is a tumor suppressor microRNA, which is related to the biological changes of many cancers. miR-1271 is considered a biomarker with a potential prognosis and high therapeutic value in tumors. Besides, the expression of miR-1271 is also regulated by many factors. In this study, we summarize the role of miR-1271 in tumors, focusing on the molecular mechanisms of the target genes of miR-1271. Our review will provide a comprehensive understanding of miR-1271 in tumors, as well as ideas for subsequent tumor research related to miR-1271.

MicroRNA‑1271‑5p alleviates the malignant development of hepatitis B virus‑mediated liver cancer via binding to AQP5

Hepatitis B virus (HBV) is a leading cause of liver-related cancer. Progress has been made on the study of microRNA (miRNA or miR) function in HBV-related liver cancer. Hence, the objective of the present study was to determine the role and functional mechanism of miR-1271-5p in HBV-associated liver cancer. miR-1271-5p and aquaporin 5 (AQP5) expression at the mRNA level were measured by reverse transcription-quantitative PCR (RT-qPCR). The levels of hepatitis B e-antigen (HBeAg), hepatitis B surface antigen (HBsAg) and HBV DNA were assessed by ELISA or qPCR. Cell viability, apoptosis, migration and invasion were detected by Cell Counting Kit-8, flow cytometry or Transwell assay. The interaction of miR-1271-5p and AQP5 was predicted by TargetScan, and verified by Dual-luciferase reporter assay and RNA binding protein immunoprecipitation assay. The protein levels of AQP5, Bax, Bcl-2, cleaved-caspase-3 and proliferating cell nuclear antigen were quantified by western blot analysis. Nude mouse tumorigenicity assay was conducted to examine the role of miR-1271-5p in vivo. miR-1271-5p was downregulated, while AQP5 was upregulated in HBV-related liver cancer cells and tissues. Overexpression of miR-1271-5p or AQP5 knockdown inhibited the levels of HBeAg, HBsAg and HBV DNA, blocked cell viability, migration and invasion, and induced apoptosis. AQP5 was confirmed to be a direct target of miR-1271-5p, and miR-1271-5p exerted its role through targeting AQP5. Overexpression of miR-1271-5p impeded tumor growth in vivo by weakening the expression of AQP5. In conclusion, miR-1271-5p blocked the progression of HBV-induced liver cancer by competitively targeting AQP5.

miRNA signature in glioblastoma: Potential biomarkers and therapeutic targets

MicroRNAs (miRNAs) are transcripts with sizes of about 22 nucleotides, which are produced through a multistep process in the nucleus and cytoplasm. These transcripts modulate the expression of their target genes through binding with certain target regions, particularly 3' suntranslated regions. They are involved in the pathogenesis of several kinds of cancers, such as glioblastoma. Several miRNAs, including miR-10b, miR-21, miR-17-92-cluster, and miR-93, have been up-regulated in glioblastoma cell lines and clinical samples. On the other hand, expression of miR-7, miR-29b, miR-32, miR-34, miR-181 family members, and a number of other miRNAs have been decreased in this type of cancer. In the current review, we explain the role of miRNAs in the pathogenesis of glioblastoma through providing a summary of studies that reported dysregulation of these epigenetic effectors in this kind of brain cancer.

The Significance of MicroRNAs Expression in Regulation of Extracellular Matrix and Other Drug Resistant Genes in Drug Resistant Ovarian Cancer Cell Lines

Ovarian cancer rates the highest mortality among all gynecological malignancies. The main reason for high mortality is the development of drug resistance. It can be related to increased expression of drug transporters and increased expression of extracellular matrix (ECM) proteins. Our foremost aim was to exhibit alterations in the miRNA expression levels in cisplatin (CIS), paclitaxel (PAC), doxorubicin (DOX), and topotecan (TOP)-resistant variants of the W1 sensitive ovarian cancer cell line-using miRNA microarray. The second goal was to identify miRNAs responsible for the regulation of drug-resistant genes. According to our observation, alterations in the expression of 40 miRNAs were present. We could observe that, in at least one drug-resistant cell line, the expression of 21 miRNAs was upregulated and that of 19 miRNAs was downregulated. We identified target genes for 22 miRNAs. Target analysis showed that miRNA regulates key genes responsible for drug resistance. Among others, we observed regulation of the ATP-binding cassette subfamily B member 1 gene (ABCB1) in the paclitaxel-resistant cell line by miR-363 and regulation of the collagen type III alpha 1 chain gene (COL3A1) in the topotekan-resistant cell line by miR-29a.

The iron chelator desferrioxamine synergizes with chemotherapy for cancer treatment

BACKGROUND

Cisplatin (CDDP) resistance remains a major obstacle for treatment of ovarian cancer. Iron contributes to the growth and reproduction of malignant cells, thus iron chalators can inhibit the growth of tumor cells by depleting the intracellular iron pool. The iron chelator, desferrioxamine (DFO), has performed anticancer in previous study. The aim of our study is to determine the correlation between iron-deprivation and tumor chemosensitivity in ovarian cancer.

METHODS

To investigate the prognostic value of ferritin light (FTL), ferroportin (FPN), hepcidin (HAMP) and divalent metal-ion transporter-1 (DMT1) in ovarian cancer, the Kaplan-Meier analysis and the Gene Expression Profiling Interactive Analysis (GEPIA) were used. The ovarian cancer cell lines (SKOV-3 and OVCAR-3) were exposed to a gradient concentration of DFO (10, 20, 50, 100, 200 μM) and CDDP (1, 5, 10, 50,100 μM) for 24 h. The protein expression of FTL was tested. The expression of cancer stem cell (CSC) markers, including Sox2, Nanog and C-myc, were downregulated with treatment of DFO. Also, the mamosphere formation and the plation of CD44^+/high/CD133^+/high and Aldehyde dehydrogenase (ALDH)^+/high SKOV-3 cells were reduced after treatment for 7d. Furthermore, we detected the expression of p53, BCL-2, BAX, and caspase-8.

RESULTS

The survival analysis revealed that high expression of FTL, DMT1, HAMP, showed poor overall survival (OS) in ovarian cancer patients. Our combined data found that DFO could effectively inhibit CSCs, improve the resistance to chemotherapy, and significantly enhanced the efficacy of CDDP therapy in vitro in promoting apoptosis. Besides, targeting molecular targets, including BAX, BCL-2, p53 and caspase-8 could serve as the clinical biomarkers to evaluate the effects of ovarian cancer. It is reasonable to believe that DFO adjuvant therapy in combination with CDDP chemotherapy can promote the improvement of treatment response in ovarian cancer patients.

CONCLUSION

Our research suggests the experimental evidence for DFO and CDDP as a new effective combination therapy to enhance the efficacy of chemical therapy in ovarian cancer.

Hydroxychloroquine potentiates the anti-cancer effect of bevacizumab on glioblastoma via the inhibition of autophagy

Bevacizumab (BEV) is widely used for the treatment of patients with recurrent glioblastoma (GBM), but recent evidence demonstrated that BEV induced cytoprotective autophagy, which allows tumor cells to survive. Hydroxychloroquine (HCQ) inhibits lysosomal acidification and blocks autophagy via influencing autophagosome fusion and degradation. HCQ is often used to enhance the efficacy of chemoradiotherapy. However, whether HCQ sensitizes GBM cells to BEV and the molecular mechanism of this effect are not clear. We showed that high concentrations of BEV increased the LC3-II/LC3-I ratio and caused the degradation of Beclin1 in the LN18 and LN229 cell lines, indicating that high concentrations of BEV induced the autophagy of the LN18 and LN229 cells. However, BEV (100 μg/ml) did not influence the autophagy of the LN18 and LN229 cells, and HCQ at less than 5 μg/ml significantly accumulated LC3B-II and p62 proteins and blocked the autophagy process. Importantly, we found that HCQ (5 μg/ml) potentiated the anti-cancer effect of BEV (100 μg/ml). Therefore, HCQ is a novel strategy that may augment the efficacy of BEV for GBM via the inhibition of autophagy.

Estrogen receptor-α-miR-1271-SNAI2 feedback loop regulates transforming growth factor-β-induced breast cancer progression

BACKGROUND

Breast cancer is the most common cancer among women worldwide, and approximately 70% of breast cancers are hormone receptor-positive and express estrogen receptor-α (ERα) or/and progesterone receptor. ERα has been identified to promote the growth of primary breast cancer, however, it can also antagonize signaling pathways that lead to epithelial-mesenchymal transition (EMT), including transforming growth factor-β (TGF-β) signaling. miRNA alteration or dysfunction is involved in cancer development and progression. Although miR-1271 has identified as a tumor suppressor in various cancers, the role of miR-1271 in breast cancer is still limited.

METHODS

The effect of miR-1271 on breast cancer progression was investigated both in vitro and in vivo. The EMT-related protein expression levels and localization were analyzed by western blotting and immunofluorescence, respectively. Chromatin immunoprecipitation and dual-luciferase reporter assays were used to validate the regulation of ERα-miR-1271-SNAI2 feedback loop.

RESULTS

miR-1271 suppresses breast cancer progression and EMT phenotype both in vitro and in vivo by targeting SNAI2. Estrogen reverses TGF-β-induced EMT in a miR-1271 dependent manner. Furthermore, ERα transactivates the miR-1271 expression and is also transcriptionally repressed by SNAI2.

CONCLUSIONS

Our data uncover the ERα-miR-1271-SNAI2 feedback loop and provide a mechanism to explain the TGF-β network in breast cancer progression.