The Role of microRNAs in the Cisplatin- and Radio-Resistance of Cervical Cancer

Exploring a novel seven-gene marker and mitochondrial gene TMEM38A for predicting cervical cancer radiotherapy sensitivity using machine learning algorithms

Background

Radiotherapy plays a crucial role in the management of Cervical cancer (CC), as the development of resistance by cancer cells to radiotherapeutic interventions is a significant factor contributing to treatment failure in patients. However, the specific mechanisms that contribute to this resistance remain unclear. Currently, molecular targeted therapy, including mitochondrial genes, has emerged as a new approach in treating different types of cancers, gaining significant attention as an area of research in addressing the challenge of radiotherapy resistance in cancer.

Methods

The present study employed a rigorous screening methodology within the TCGA database to identify a cohort of patients diagnosed with CC who had received radiotherapy treatment. The control group consisted of individuals who demonstrated disease stability or progression after undergoing radiotherapy. In contrast, the treatment group consisted of patients who experienced complete or partial remission following radiotherapy. Following this, we identified and examined the differentially expressed genes (DEGs) in the two cohorts. Subsequently, we conducted additional analyses to refine the set of excluded DEGs by employing the least absolute shrinkage and selection operator regression and random forest techniques. Additionally, a comprehensive analysis was conducted in order to evaluate the potential correlation between the expression of core genes and the extent of immune cell infiltration in patients diagnosed with CC. The mitochondrial-associated genes were obtained from the MITOCARTA 3.0. Finally, the verification of increased expression of the mitochondrial gene TMEM38A in individuals with CC exhibiting sensitivity to radiotherapy was conducted using reverse transcription quantitative polymerase chain reaction and immunohistochemistry assays.

Results

This process ultimately led to the identification of 7 crucial genes, viz., GJA3, TMEM38A, ID4, CDHR1, SLC10A4, KCNG1, and HMGCS2, which were strongly associated with radiotherapy sensitivity. The enrichment analysis has unveiled a significant association between these 7 crucial genes and prominent signaling pathways, such as the p53 signaling pathway, KRAS signaling pathway, and PI3K/AKT/MTOR pathway. By utilizing these 7 core genes, an unsupervised clustering analysis was conducted on patients with CC, resulting in the categorization of patients into three distinct molecular subtypes. In addition, a predictive model for the sensitivity of CC radiotherapy was developed using a neural network approach, utilizing the expression levels of these 7 core genes. Moreover, the CellMiner database was utilized to predict drugs that are closely linked to these 7 core genes, which could potentially act as crucial agents in overcoming radiotherapy resistance in CC.

Conclusion

To summarize, the genes GJA3, TMEM38A, ID4, CDHR1, SLC10A4, KCNG1, and HMGCS2 were found to be closely correlated with the sensitivity of CC to radiotherapy. Notably, TMEM38A, a mitochondrial gene, exhibited the highest degree of correlation, indicating its potential as a crucial biomarker for the modulation of radiotherapy sensitivity in CC.

Evaluation of Long Non-coding RNA (LncRNA) in the Pathogenesis of Chemotherapy Resistance in Cervical Cancer: Diagnostic and Prognostic Approach

Cervical cancer (CC), caused by human papillomavirus (HPV), is a leading cause of female malignancies worldwide. Therefore, understanding the underlying mechanisms of CC development and identifying novel therapeutic targets are significantly important. Cisplatin resistance is a significant challenge in the management of CC. Recent studies highlighted the critical role of long non-coding RNAs (lncRNAs) in modulation of cisplatin resistance. This comprehensive review aims to collect the current understanding roles of lncRNAs and their involvement in cisplatin resistance in CC by highlighting key processes of cancer progression, including apoptosis, proliferation, angiogenesis and epithelial-to-mesenchymal transition (EMT). We discussed the role of lncRNA in CC resistance to cisplatin through molecular pathways and examined gene expression changes. We also discussed treatment strategies and factors that reduce CC resistance to cisplatin by targeting them.

USF1 regulated circPRDM4 modulates tumorigenesis and immune escape in chemoresistant cervical cancer

Cervical cancer (CC) represents a major global health concern, characterized by chemoresistance and immune evasion mechanisms. Circular RNAs (circRNAs), which play a crucial role in cancer pathogenesis, particularly in the case of CC, have gained significant attention. The primary objective of this study was to investigate the functional significance of circRNAs in chemoresistant CC. A significant upregulation of circPRDM4 expression in chemoresistant CC cells. To investigate the functional consequences, we conducted circPRDM4 knockdown experiments, which resulted in the effective blockade of immune escape mechanisms employed by chemoresistant CC cells. Furthermore, circPRDM4 knockdown demonstrated a significant suppression of tumorigenesis in CC cells, highlighting its contribution to the oncogenic potential of CC. Investigating the regulatory mechanisms involved, we found that the transcriptional factor upstream stimulatory factor 1 (USF1) acts as an inducer of circPRDM4 expression. Remarkably, USF1 was found to effectively modulate CC cell immune escape via its interaction with circPRDM4. Moreover, our results revealed that USF1 is intricately involved in CC cell tumorigenesis through the regulation of circPRDM4. Collectively, our study elucidates the significant roles of circPRDM4 and its upstream regulator USF1 in chemoresistant CC cells. These findings underscore the importance of circRNAs in CC pathogenesis and provide valuable insights into the mechanisms underlying immune escape and tumorigenesis.

Two Enhances the Cisplatin Sensitivity of Cervical Cancer Cells via Suppression of c-MET Expression

Background

The drug resistance of chemotherapeutic agents leads to unsatisfactory survival rates for cervical cancer (CC) patients. We aimed to explore the effect of FOXP2 on the sensitivity of CC cells to cisplatin (DDP) and its mechanism in Changde, China in 2018.

Methods

A Total of 6 cervical cancer tissue samples including 3 patients with cisplatin sensitivity and 3 patients with cisplatin resistance, who received DDP-based treatment, were obtained from Changde First People's Hospital, Changde City during 2021, and FOXP2 level was detected by Western blot. The expression levels of FOXP2 and c-MET (hepatocyte growth factor receptor, c-MET) in cells were determined by q-PCR and Western blot analysis. The cell survival, apoptosis, and clone formation were analyzed by flow cytometry, MTT assay, or clone formation assay. Dual-luciferase reporter assays and Chromatin immunoprecipitation were applied to verify the regulation between FOXP2 and c-MET.

Results

FOXP2 was downregulated in cisplatin-resistant cervical cancer tissues and cells compared with control. FOXP2 overexpression in SiHa/DDP cells inhibited cell proliferation and promoted cell apoptosis, whereas down-regulation of FOXP2 in SiHa cells had the opposite result. FOXP2 enhanced chemosensitive to DDP in CC cells. FOXP2 is negatively correlated with c-MET expression level in SiHa and SiHa/DDP cells. Mechanistically, FOXP2 binds to the promoter region of c-MET to regulate its expression in CC cells negatively. Overexpression of c-MET can attenuate the enhancement of DDP-induced apoptosis caused by FOXP2 overexpression.

Conclusion

This is a novel study on the role of FOXP2 in promoting the DDP sensitivity of CC cells by inhibiting c-MET. The FOXP2/c-MET signaling axis uncovered in the present study may be a novel therapeutic target for the DDP therapy resistance of CC.

BRSK1 confers cisplatin resistance in cervical cancer cells via regulation of mitochondrial respiration

PURPOSE

Although cisplatin-containing chemotherapy has been utilized as a front-line treatment for cervical cancer, intrinsic and acquired resistance of cisplatin remains a major hurdle for the durable and curative therapeutic response. We thus aim to identify novel regulator of cisplatin resistance in cervical cancer cells.

METHODS

Real-time PCR and western blotting analysis were employed to determine the expression of BRSK1 in normal and cisplatin-resistant cells. Sulforhodamine B assay was conducted to assess the sensitivity of cervical cancer cells to cisplatin. Seahorse Cell Mito Stress Test assay was utilized to evaluate the mitochondrial respiration in cervical cancer cells.

RESULTS

BRSK1 expression was upregulated in cisplatin-treated cervical cancer patient tumors and cell lines compared with untreated tumors and cell lines. Depletion of BRSK1 significantly enhanced the sensitivity of both normal and cisplatin-resistant cervical cancer cells to cisplatin treatment. Moreover, BRSK1-mediated regulation of cisplatin sensitivity is conducted by a subpopulation of BRSK1 residing in the mitochondria of cervical cancer cells and is dependent on its kinase enzymatic activity. Mechanistically, BRSK1 confers cisplatin resistance via the regulation of mitochondrial respiration. Importantly, treatment with mitochondrial inhibitor in cervical cancer cells phenocopied the BRSK1 depletion-mediated mitochondria dysfunction and cisplatin sensitization. Of note, we observed that high BRSK1 expression is correlated with poor prognosis in cisplatin-treated cervical cancer patients.

CONCLUSION

Our study defines BRSK1 as a novel regulator of cisplatin sensitivity, identifying that targeting BRSK1-regulated mitochondrial respiration could be a useful approach for enhancing the efficacy of cisplatin-based chemotherapy in cervical cancer patients.

Circ_0085616 contributes to the radio-resistance and progression of cervical cancer by targeting miR-541-3p/ARL2 signaling

BACKGROUND

Circular RNAs (circRNAs) play crucial regulatory roles in cancer progression and the development of radio-resistance. Here, we intended to explore the role of circ_0085616 in cervical cancer progression and its associated mechanism.

METHODS

Colony formation assay was employed to analyze the radio-resistance and proliferation of cervical cancer cells. Cell proliferation ability was also assessed by 5-ethynyl-2'-deoxyuridine (EdU) assay. Cell apoptosis was analyzed by flow cytometry. Tube formation assay was performed to analyze cell angiogenesis ability. Transwell assays were conducted to measure cell migration and invasion abilities. Dual-luciferase reporter assay was utilized to verify the target relationships. Xenograft mice model was used to analyze the role of circ_0085616 in tumor growth in vivo.

RESULTS

Circ_0085616 expression was elevated in cervical cancer tissues and cell lines. Circ_0085616 interference suppressed the radio-resistance, proliferation, tube formation, migration, and invasion and elevated the apoptosis rate of cervical cancer cells. Circ_0085616 acted as a sponge for microRNA-541-3p (miR-541-3p), and miR-541-3p was negatively regulated by circ_0085616 in cervical cancer cells. Circ_0085616 absence-induced changes in the behaviors of cervical cancer cells were largely overturned by anti-miR-541-3p. miR-541-3p negatively regulated ADP ribosylation factor like GTPase 2 (ARL2) expression by binding to its 3' untranslated region (3'UTR). miR-541-3p mimic-induced effects were largely reversed by pcDNA-ARL2 in cervical cancer cells. Circ_0085616 positively regulated ARL2 expression by sequestering miR-541-3p. Circ_0085616 absence significantly inhibited the tumor growth in vivo.

CONCLUSION

Circ_0085616 contributed to the radio-resistance and progression of cervical cancer partly through mediating the miR-541-3p/ARL2 axis.

Circular RNA ARHGAP5 inhibits cisplatin resistance in cervical squamous cell carcinoma by interacting with AUF1

Cervical squamous cell carcinoma (CSCC) is one of the leading causes of cancer death in women worldwide. Patients with advanced cervical carcinoma always have a poor prognosis once resistant to cisplatin due to the lack of effective treatment. It is urgent to investigate the molecular mechanisms of cisplatin resistance. Circular RNAs (circRNAs) are known to exert their regulatory functions in a series of malignancies. However, their effects on CSCC remain to be elucidated. Here, we found that cytoplasmic circARHGAP5, derived from second and third exons of the ARHGAP5 gene, was downregulated in cisplatin-resistant tissues compared with normal cervix tissues and untreated cervical cancer tissues. In addition, experiments from overexpression/knockdown cell lines revealed that circARHGAP5 could inhibit cisplatin-mediated cell apoptosis in CSCC cells both in vitro and in vivo. Mechanistically, circARHGAP5 interacted with AU-rich element RNA-binding protein (AUF1) directly. Overexpression of AUF1 could also inhibit cell apoptosis mediated by cisplatin. Furthermore, we detected the potential targets of AUF1 related to the apoptotic pathway and found that bcl-2-like protein 11 (BIM) was not only negatively regulated by AUF1 but positively regulated by circARHGAP5, which indicated that BIM mRNA might be degraded by AUF1 and thereby inhibited tumor cell apoptosis. Collectively, our data indicated that circARHGAP5 directly bound to AUF1 and prevented AUF1 from interacting with BIM mRNA, thereby playing a pivotal role in cisplatin resistance in CSCC. Our study provides insights into overcoming cancer resistance to cisplatin treatment.

Engineered exosomes from different sources for cancer-targeted therapy

Exosome is a subgroup of extracellular vesicles, which has been serving as an efficient therapeutic tool for various diseases. Engineered exosomes are the sort of exosomes modified with surface decoration and internal therapeutic molecules. After appropriate modification, engineered exosomes are able to deliver antitumor drugs to tumor sites efficiently and precisely with fewer treatment-related adverse effects. However, there still exist many challenges for the clinical translation of engineered exosomes. For instance, what sources and modification strategies could endow exosomes with the most efficient antitumor activity is still poorly understood. Additionally, how to choose appropriately engineered exosomes in different antitumor therapies is another unresolved problem. In this review, we summarized the characteristics of engineered exosomes, especially the spatial and temporal properties. Additionally, we concluded the recent advances in engineered exosomes in the cancer fields, including the sources, isolation technologies, modification strategies, and labeling and imaging methods of engineered exosomes. Furthermore, the applications of engineered exosomes in different antitumor therapies were summarized, such as photodynamic therapy, gene therapy, and immunotherapy. Consequently, the above provides the cancer researchers in this community with the latest ideas on engineered exosome modification and new direction of new drug development, which is prospective to accelerate the clinical translation of engineered exosomes for cancer-targeted therapy.

Targeting the NRF2/KEAP1 pathway in cervical and endometrial cancers

Cervical and endometrial cancers are among the most dangerous gynaecological malignancies, with high fatality and recurrence rates due to frequent diagnosis at an advanced stage and chemoresistance onset. The NRF2/KEAP1 signalling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. NRF2, activated by ROS, induces the expression of antioxidant enzymes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase which neutralize ROS, protecting cells against oxidative stress damage. However, activation of NRF2/KEAP1 signalling in cancer cells results in chemoresistance, inactivating drug-mediated oxidative stress and protecting cancer cells from drug-induced cell death. We review the literature on the role of the NRF2/KEAP1 pathway in cervical and endometrial cancers, with a focus on the expression of its components and downstream genes. We also examine the role of the NRF2/KEAP1 pathway in chemotherapy resistance and how this pathway can be modulated by natural and synthetic modulators.

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

Background

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

Methods

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

Results

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

Conclusion

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

Emerging role of interaction between m6A and main ncRNAs in gastrointestinal (GI) cancers

As a prevalent epigenetic modification, the role of m6A has been increasingly highlighted in the alteration of numerous RNAs implicated with multiple biological processes, such as formation, export, translation, and degradation. With further the understanding of m6A, accumulating evidence shows that m6A modification similarly affects metabolic process of non-coding genes. But the specifical interplay of m6A and ncRNAs (non-coding RNAs) in gastrointestinal cancers still lacks complete discussion. Thus, we analyzed and summarized how ncRNAs affect the regulators of m6A and by what means the expression of ncRNAs is altered via m6A in gastrointestinal cancers. We focused on the effect of the interaction of m6A and ncRNAs on the molecular mechanisms of malignant behavior in gastrointestinal cancers, revealing more possibilities of ncRNAs for diagnosis and treatment in term of epigenetic modification.

Circular RNA circ_0005667 promotes cisplatin resistance of endometrial carcinoma cells by regulating IGF2BP1 through miR-145-5p

BACKGROUND

Circular RNA (circRNA) plays a significant role in cisplatin (DDP) resistance. The purpose of this study was to explore the role of circ_0005667 in DDP resistance of endometrial carcinoma (EC) cells.

METHODS

The expression of circular RNA circ_0005667, microRNA-145-5p (miR-145-5p) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in DDP-sensitive and DDP-resistant EC tissues and EC cells was determined by quantitative real-time PCR (qRT-PCR). The expression of apoptosis-related proteins, drug resistance-related proteins and IGF2BP1 proteins were detected by western blot. The half-maximal inhibitory concentration (IC50) of DDP was determined using a cell counting kit-8 (CCK-8) assay. For functional assays, cell proliferation, migration, invasion and cell apoptosis were determined using 5-ethynyl-2'-deoxyuridine (EdU) assay, wound healing assay, transwell assay and flow cytometry assay, respectively. The binding relationship between miR-145-5p and circ_0005667 or IGF2BP1 was verified by dual-luciferase reporter assay. A xenograft experiment was applied to clarify the functional role of circ_0005667 in vivo.

RESULTS

Levels of circ_0005667 and IGF2BP1 were markedly increased, whereas miR-145-5p was downregulated in DDP-resistant EC tissues and cells. The circ_0005667 deficiency could enhance DDP sensitivity, inhibit cell proliferation, migration and invasion and promote cell apoptosis in DDP-resistant EC cells in vitro. Mechanistically, circ_0005667 modulated IGF2BP1 expression through sponging miR-145-5p. In addition, miR-145-5p depletion attenuated circ_0005667 silencing-induced effects in EC cells. The regulation of miR-145-5p in DDP resistance involved low IGF2BP1 expression. In vivo experiments revealed that circ_0005667 silencing could improve the sensitivity of the tumor to DDP.

CONCLUSION

Circ_0005667 enhanced DDP resistance in EC by elevating IGF2BP1 through sponging miR-145-5p.

Icariin-Mediated miR-875-5p Inhibits Autophagy and Epithelial-Mesenchymal Transition by Regulation of MDM4 in Cervical Cancer

MicroRNAs, one type of non-coding RNA, and Icariin have attracted tremendous attention concerning various diseases, especially cancers. Also, the function of Icariin on malignant behaviors by targeting miR-875-5p/MDM4 axis in cervical cancer remains unknown. MiR-875-5p analogs combined with MDM4 or Icariin were used to explore autophagy and epithelial-mesenchymal transition in cancer cells. Xenograft mice were highlighted to elucidate the influences of Icariin and miR-875-5p in vivo. As a result, miR-875-5p was cut down in cervical cancer cells, which promoted malignant phenotype, autophagy, and limited apoptosis in cervical cancer cells. Contrarily,miR-875-5p overexpression had a contrary performance in cervical cancer cells. miR-875-5p was validated as a sponge of MDM4. Enhanced expression of MDM4 weakened the performance of miR-875-5p mimic on autophagy and epithelial-mesenchymal transition. Moreover, Icariin reversed the stimulative action of the inhibitor on autophagy and xenograft tumor growth. Generally, These findings imply that Icariin could be identified as a curative avenue for cervical cancer via miR-875-5p/MDM4 axis.

miR-96-5p regulates cervical cancer cell resistance to cisplatin by inhibiting lncRNA TRIM52-AS1 and promoting IGF2BP2

MicroRNA (miRNA) and long noncoding RNA (lncRNA) are both regulators of cancer progression. This study sought to discuss the functional mechanism of miR-96-5p/lncRNA TRIM52 antisense RNA 1 (head-to-head; TRIM52-AS1) in cervical cancer (CC) cell resistance to cisplatin (DDP). DDP-resistant CC cell line was established using increasing concentrations of DDP, followed by transfection with miR-96-5p inhibitor, or si-TRIM52-AS1, or insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) overexpression vector. Expression levels of miR-96-5p, TRIM52-AS1, and IGF2BP2 were determined. Changes in IC50 value to DDP, cell proliferation, and apoptosis rate were evaluated by cell-counting kit-8 assay, colony formation, and flow cytometry. The bindings of miR-96-5p to IGF2BP2 and TRIM52-AS1 to IGF2BP2 were verified by dual-luciferase or RNA pull-down assays. These experiments revealed an up-expression of miR-96-5p and IGF2BP2 while an under-expression of TRIM52-AS1 in CC cells. After DDP treatment, miR-96-5p inhibition increased apoptosis and decreased proliferation and DDP resistance. miR-96-5p bound to TRIM52-AS1 and downregulated TRIM52-AS1 expression, and TRIM52-AS1 bound to IGF2BP2 to inhibit IGF2BP2 expression. TRIM52-AS1 inhibition or IGF2BP2 overexpression neutralized the inhibition of silencing miR-96-5p on CC cell resistance to DDP. Overall, miR-96-5p improved CC cell resistance to DDP by inhibiting TRIM52-AS1 and promoting IGF2BP2.

Cervical cancer heterogeneity: a constant battle against viruses and drugs

Cervical cancer is the first identified human papillomavirus (HPV) associated cancer and the most promising malignancy to be eliminated. However, the ever-changing virus subtypes and acquired multiple drug resistance continue to induce failure of tumor prevention and treatment. The exploration of cervical cancer heterogeneity is the crucial way to achieve effective prevention and precise treatment. Tumor heterogeneity exists in various aspects including the immune clearance of viruses, tumorigenesis, neoplasm recurrence, metastasis and drug resistance. Tumor development and drug resistance are often driven by potential gene amplification and deletion, not only somatic genomic alterations, but also copy number amplifications, histone modification and DNA methylation. Genomic rearrangements may occur by selection effects from chemotherapy or radiotherapy which exhibits genetic intra-tumor heterogeneity in advanced cervical cancers. The combined application of cervical cancer therapeutic vaccine and immune checkpoint inhibitors has become an effective strategy to address the heterogeneity of treatment. In this review, we will integrate classic and recently updated epidemiological data on vaccination rates, screening rates, incidence and mortality of cervical cancer patients worldwide aiming to understand the current situation of disease prevention and control and identify the direction of urgent efforts. Additionally, we will focus on the tumor environment to summarize the conditions of immune clearance and gene integration after different HPV infections and to explore the genomic factors of tumor heterogeneity. Finally, we will make a thorough inquiry into completed and ongoing phase III clinical trials in cervical cancer and summarize molecular mechanisms of drug resistance among chemotherapy, radiotherapy, biotherapy, and immunotherapy.

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer

BACKGROUND

Chemoresistance is one of the major obstacles that lead to poor prognosis in cervical cancer. linc00958 was reported to be an oncogene in cervical cancer. However, its role in mediating chemoresistance remains to be revealed.

PURPOSE

To explore the regulatory mechanisms of linc00958 in cisplatin-resistant cervical cancer cells and further validate in xenograft mice.

METHODS

Online bioinformatic tools were used to conduct the pre-investigation of linc00958/miR-185-5p/RSF-1 and predict the associations between RSF-1 and AKT1/GSK3β/VEGFA in cervical cancer. RT-qPCR measured the RNA expression levels of linc00958/miR-185-5p/RSF-1 in SiHa and SiHa/DDP. Cell survival rates were evaluated by CCK8 methods after cells were exposed to differential concentrations of DDP. Dual-luciferase reporter methods were used to measure luciferase activity. Western blot measured RSF-1 protein and phosphorylated changes of AKT1/GSK3β. Immunofluorescence was employed to observe VEGFA secretion in vitro. Tube formation was applied to evaluate the in-vitro changes of angiogenesis. The SiHa/DDP cells stably transfected with pLKO-sh-NC or pLKO-sh-linc00958 plasmids, were injected into mice, establishing xenograft models. The changes in mice weight and tumor volumes were recorded. H&E staining and Immunohistochemistry (IHC) method was further performed.

RESULTS

linc00958 expression was higher in SiHa/DDP cells. High linc00958 expression was associated with low overall survival. In SiHa/DDP cells linc00958/miR-185-5p/RSF-1 axis inhibited the cellular resistance to cisplatin and suppressed VEGFA and the tube formation through AKT1/GSK3β/VEGFA pathway. The knockdown of linc00958 inhibited RSF-1 and Ki67, curbing tumor growth; it also inhibited VEGFA and CD34, decreasing angiogenesis in mice.

CONCLUSION

linc00958/miR-185-5p/RSF-1 modulates cisplatin resistance and angiogenesis through AKT1/GSK3β/VEGFA pathway in cervical cancer.

Cisplatin for cancer therapy and overcoming chemoresistance

Cisplatin spearheads the anticancer chemotherapeutics in present-day use although acute toxicity is its primary impediment factor. Among a plethora of experimental medications, a drug as effective or surpassing the benefits of cisplatin has not been discovered yet. Although Oxaliplatin is considered more superior to cisplatin, the former has been better for colorectal cancer while cisplatin is widely used for treating gynaecological cancers. Carcinoma imposes a heavy toll on mortality rates worldwide despite the novel treatment strategies and detection methods that have been introduced; nanomedicine combined with precision medicine, immunotherapy, volume-regulated anion channels, and fluorodeoxyglucose-positron emission tomography. Millions of deaths occur annually from metastatic cancers which escape early detection and the concomitant diseases caused by highly toxic chemotherapy that causes organ damage. It continues due to insufficient knowledge of the debilitative mechanisms induced by cancer biology. To overcome chemoresistance and to attenuate the adverse effects of cisplatin therapy, both in vitro and in vivo models of cisplatin-treated cancers and a few multi-centred, multi-phasic, randomized clinical trials in pursuant with recent novel strategies have been tested. They include plant-based phytochemical compounds, de novo drug delivery systems, biochemical/immune pathways, 2D and 3D cell culture models using small molecule inhibitors and genetic/epigenetic mechanisms, that have contributed to further the understanding of cisplatin's role in modulating the tumour microenvironment. Cisplatin was beneficial in cancer therapy for modulating the putative cellular mechanisms; apoptosis, autophagy, cell cycle arrest and gene therapy of micro RNAs. Specific importance of drug influx, efflux, systemic circulatory toxicity, half-maximal inhibition, and the augmentation of host immunometabolism have been identified. This review offers a discourse on the recent anti-neoplastic treatment strategies to enhance cisplatin efficacy and to overcome chemoresistance, given its superiority among other tolerable chemotherapies.

Downregulation of miR-21 as a promising strategy to overcome drug resistance in cancer

Despite tremendous achievements in the field of targeted cancer therapy, chemotherapy is still the main treatment option, which is challenged by acquired drug resistance. Various microRNAs are involved in developing drug-resistant cells. miR-21 is one of the first identified miRNAs involved in this process. Here, we conducted a literature review to categorize different mechanisms employed by miR-21 to drive drug resistance. miR-21 targets various genes involved in many pathways that can justify chemoresistance. It alters cancer cell metabolism and facilitates adaptation to the new environment. It also enhances drug detoxification in cancerous cells and increases genomic instability. We also summarized various strategies applied for the inhibition of miR-21 in order to reverse cancer drug resistance. These strategies include the delivery of antagomiRs, miRZip knockdown vectors, inhibitory small molecules, CRISPR-Cas9 technology, catalytic nucleic acids, artificial DNA and RNA sponges, and nanostructures like mesoporous silica nanoparticles, dendrimers, and exosomes. Furthermore, current challenges and limitations in targeting miR-21 are discussed in this article. Although huge progress has been made in the downregulation of miR-21 in drug-resistant cancer cells, there are still many challenges to be resolved. More research is still required to find the best strategy and timeline for the downregulation of miR-21 and also the most feasible approach for the delivery of this system into the tumor cells. In conclusion, downregulation of miR-21 would be a promising strategy to reverse chemoresistance, but still, more studies are required to clarify the aforementioned issues.

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.

Role of NRF2 in Ovarian Cancer

Among gynaecologic malignancies, ovarian cancer is one of the most dangerous, with a high fatality rate and relapse due to the occurrence of chemoresistance. Many researchers demonstrated that oxidative stress is involved in tumour occurrence, growth and development. Nuclear factor erythroid 2-related factor 2 (NRF2) is an important transcription factor, playing an important role in protecting against oxidative damage. Increased levels of Reactive Oxygen Species (ROS) activate NRF2 signalling, inducing the expression of antioxidant enzymes, such as haem oxygenase (HO-1), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), that protect cells against oxidative stress. However, NRF2 activation in cancer cells is responsible for the development of chemoresistance, inactivating drug-mediated oxidative stress that normally leads to cancer cells’ death. In this review, we report evidence from the literature describing the effect of NRF2 on ovarian cancer, with a focus on its function in drug resistance, NRF2 natural and synthetic modulators and its protective function in normal ovarian preservation.

ADGRG1 Is a Predictor of Chemoresistance and Poor Survival in Cervical Squamous Carcinoma

Background

Cisplatin is the first-line chemotherapy for cervical cancer. Cisplatin resistance has always been one of the most significant barriers to acquiring better outcomes. However, the complex molecular mechanisms accounting for the phenomenon are not completely clear.

Methods

Construction of the cisplatin-resistant cell model of cervical cancer, then performing RNA sequencing and bioinformatic analysis of the differential expression genes. Then Adhesion G protein-coupled receptor G1 (ADGRG1) was screened out as our target gene. Gene Expression Profiling Interactive Analysis (GEPIA) was searched to show the expression level of ADGRG1 in cervical cancer and normal tissue. Kaplan-Meier Plotter (Kmplot) was used to explore the relationship of its expression with survival data. Tissue specimens were used to verify the relationship between the clinicopathological characteristics and ADGRG1 expression. Then we explored the roles of ADGRG1 in tumorigenesis through in vitro and in vivo assays.

Results

We found the ADGRG1 was significantly overexpressed in cervical cancer tissues compared to corresponding normal tissues. Higher ADGRG1 expression was correlated with poor progress-free survival. Knockdown of ADGRG1 markedly suppressed cell proliferation, migration, and invasion and increased cell sensitivity to cisplatin in vitro. Similarly, the role of ADGRG1 knockdown on tumorigenicity and sensitivity to cisplatin treatment was verified in vivo. The underlying mechanism was explored by western blotting that ADGRG1 knockdown inhibited tumorigenesis by PI3K/Akt/mTOR signaling pathway.

Conclusion

ADGRG1 acts as an oncogene to maintain tumorigenicity, migration, and invasion, and its depressed expression prompts sensitivity to cisplatin. Thus, ADGRG1 may represent a potential prognostic marker and possible therapeutic target for cervical cancer.