CRNDE inducing cisplatin resistance through SRSF1/TIA1 signaling pathway in ovarian cancer

Salidroside overcomes cisplatin resistance in ovarian cancer via the inhibition of CRNDE-mediated autophagy

Cisplatin (DDP) resistance significantly affects the survival rate of patients with ovarian cancer (OC). Autophagy is recognized as a common cause of resistance to DDP. This study aimed to investigate the impact of salidroside on OC progression and explore its potential regulatory effects on DDP resistance and autophagy. A DDP-resistant A2780 (A2780/DDP) cell line was induced by exposure to increasing DDP concentrations. The protein levels of autophagy proteins (p62, Beclin-1, ATG5, and LC3 II/LC3 I), apoptosis proteins (cleaved caspase-3 and cleaved caspase-9), and PI3K/AKT/mTOR pathway were determined by western blotting. Autophagic vacuoles in cells were observed with LC3 dyeing with confocal fluorescent microscopy. Cell viability and apoptosis were evaluated by cell counting kit-8 assays and flow cytometry. RT-qPCR was conducted to measure the relative levels of various lncRNAs in A2780 or A2780/DDP cells. A xenograft model was established by subcutaneous injection of 1 × 107 A2780 cells into the posterior flank of nude mice. Tumor size and weight were recorded. The expression of Ki67, cleaved caspase-3 and LC3 in tumor tissues was assessed by immunohistochemistry staining. The biodistribution of DDP in organs and blood of normal nude mice and tumors of tumor-bearing mice was detected using the ICP-MS. Hematoxylin-eosin staining was used to assess the histopathological changes of kidney, liver, and spleen sections. For in vitro analysis, autophagy was enhanced in DDP-resistant A2780 cells. Additionally, salidroside inhibits DDP resistance to A2780 cells via autophagy inhibition. Mechanistically, salidroside downregulated CRNDE in DDP-resistant A2780 cells. CRNDE knockdown inhibited autophagy, while CRNDE overexpression reversed the protective effects of salidroside. Additionally, salidroside activated the PI3K/AKT/mTOR pathway in DDP-resistant A2780 cells, and inhibition of PI3K reversed the effect of salidroside on inhibiting autophagy and apoptosis of A2780/DDP cells. For in vivo analysis, salidroside inhibited tumor growth, autophagy, and nephrotoxicity of DDP. Additionally, salidroside downregulated CRNDE and activated PI3K/AKT/mTOR signaling in vivo. Salidroside prevents autophagy-mediated DDP resistance in OC by downregulating lncRNA CRNDE and activating the PI3K/AKT/mTOR pathway.

Latest Update on lncRNA in Epithelial Ovarian Cancer-A Scoping Review

Long noncoding RNAs (lncRNAs) are RNA molecules exceeding 200 nucleotides that do not encode proteins yet play critical roles in regulating gene expression at multiple levels, such as chromatin modification and transcription. These molecules are significantly engaged in cancer progression, development, metastasis, and chemoresistance. However, the function of lncRNAs in epithelial ovarian cancer (EOC) has not yet been thoroughly studied. EOC remains challenging due to its complex molecular pathogenesis, characterized by genetic and epigenetic alterations. Emerging evidence suggests that lncRNAs, such as XIST, H19, NEAT1, and MALAT1, are involved in EOC by modulating gene expression and signaling pathways, influencing processes like cell proliferation, invasion, migration, and chemoresistance. Despite extensive research, the precise mechanism of acting of lncRNAs in EOC pathogenesis and treatment resistance still needs to be fully understood, highlighting the need for further studies. This review aims to provide an updated overview of the current understanding of lncRNAs in EOC, emphasizing their potential as biomarkers and therapeutic targets. We point out the gaps in the knowledge regarding lncRNAs' influence on epithelial ovarian cancer (EOC), deliberating on new possible research areas.

Design and synthesis of novel sulfur-substituted triptolide with the ability to induce autophagy through inhibition of SRSF1 expression

Six sulfur-substituted triptolide (TPL) analogs (STP1-6) were synthesized and evaluated for their biological functions. Among them, STP2 had significant antitumor activity both in vitro and in vivo. Notably, the intraperitoneal injections of 1 g/kg STP2 did not cause mice death and apparent pathological damage, while the mice in the TPL group (2 mg/kg) lost weight and all died within 4 days. The antitumor effect of STP2 could mediated by the inhibition of SRSF1 expression to regulate Bcl-x pre-mRNA splicing, which in turn induces autophagy and promotes cell death. This mechanism was the first time discovered in the field of TPL research. These results indicated that compound STP2 could be a promising lead compound for further studies.

Cyperotundone promotes chemosensitivity of breast cancer via SRSF1

Breast cancer is among the most common malignancies and the leading cause of cancer-related deaths in women. SRSF1 proteins belong to an important splicing factor (SF) family and bind to different splicing regulatory elements (SREs) to promote or inhibit splicing, such as oncogenic splice-switching of PTpMT1, which promoting the progression of cancer. Cyperotundone (CYT) is the major bioactive component of sedge and reported to exhibit multiple biological functions, including its potent cytotoxic effect on breast cancer cells. However, the detailed impact and molecular mechanisms of CYT in breast cancer remain poorly understood. This study aimed to investigate the effects of CYT on breast cancer drug resistance and to explore the molecular mechanisms. CYT significantly suppressed the in vitro and in vivo growth of BC cells without affecting the normal cells at different doses (P < 0.001), induced cell apoptosis, and inhibited the migration and invasion of drug-resistant BC. In comparison with the mono treatment with CYT, combination of CYT and doxorubicin (Dox) enhanced the effects. CYT treatment regulated the RNA and protein levels of epithelial mesenchymal transition (EMT) biomarkers, suppressed the sphere formation ability and expression of cancer stem cell biomarkers in drug resistant BC cells. Results from transcriptome sequencing analysis and experiments identified significantly decreased SRSF1 level in drug resistant cells after CYT treatment. RNA and protein levels of SRSF1 and MYO1B were higher in drug resistant BC cells (P < 0.01). SRSF1 regulated alternative splicing of MYO1B to enhance the ability of drug resistance. Knockdown of SRSF1 significantly decreased expression of full-length MYO1B protein in drug-resistant BC cells (P < 0.05). Overexpression of SRSF1 and MYO1B revered the inhibitory effects of CYT. In conclusion, CYT repressed the growth and metastasis of BC cells and recovered drug sensitivity, through SRSF1-regulated the alternative splicing of MYO1B RNAs, which may represent a novel molecular mechanism to overcome drug resistance in breast cancer. Targeting SRSF1 or MYO1B may be identified as a novel molecular mechanism to against drug resistant in breast cancer.

Long Non-Coding RNAs in Ovarian Cancer: Mechanistic Insights and Clinical Applications

Background/Objectives: Ovarian cancer is a leading cause of gynecological cancer mortality worldwide, often diagnosed at advanced stages due to vague symptoms and the lack of effective early detection methods. Long non-coding RNAs (lncRNAs) have emerged as key regulators in cancer biology, influencing cellular processes such as proliferation, apoptosis, and chemoresistance. This review explores the multifaceted roles of lncRNAs in ovarian cancer pathogenesis and their potential as biomarkers and therapeutic targets. Methods: A comprehensive literature review was conducted to analyze the structural and functional characteristics of lncRNAs and their contributions to ovarian cancer biology. This includes their regulatory mechanisms, interactions with signaling pathways, and implications for therapeutic resistance. Advanced bioinformatics and omics approaches were also evaluated for their potential in lncRNA research. Results: The review highlights the dual role of lncRNAs as oncogenes and tumor suppressors, modulating processes such as cell proliferation, invasion, and angiogenesis. Specific lncRNAs, such as HOTAIR and GAS5, demonstrate significant potential as diagnostic biomarkers and therapeutic targets. Emerging technologies, such as single-cell sequencing, provide valuable insights into the tumor microenvironment and the heterogeneity of lncRNA expression. Conclusions: LncRNAs hold transformative potential in advancing ovarian cancer diagnosis, prognosis, and treatment. Targeting lncRNAs or their associated pathways offers promising strategies to overcome therapy resistance and enhance personalized medicine. Continued research integrating omics and bioinformatics will be essential to unlock the full clinical potential of lncRNAs in ovarian cancer management.

Proto-oncogene c-Myb potentiates cisplatin resistance of ovarian cancer cells by downregulating lncRNA NKILA and modulating cancer stemness and LIN28A-let7 axis

Ovarian cancer is a major gynecological cancer that has poor prognosis associated mainly to its late diagnosis. Cisplatin is an FDA approved ovarian cancer therapy and even though the therapy is initially promising, the patients mostly progress to resistance against cisplatin. The underlying mechanisms are complex and not very clearly understood. Using two different paired cell lines representing cisplatin-sensitive and the cisplatin-resistant ovarian cancer cells, the ES2 and the A2780 parental and cisplatin-resistant cells, we show an elevated proto-oncogene c-Myb in resistant cells. We further show down-regulated lncRNA NKILA in resistant cells with its de-repression in resistant cells when c-Myb is silenced. NKILA negatively correlates with cancer cell and invasion but has no effect on cellular proliferation or cell cycle. C-Myb activates NF-κB signaling which is inhibited by NKILA. The cisplatin resistant cells are also marked by upregulated stem cell markers, particularly LIN28A and OCT4, and downregulated LIN28A-targeted let-7 family miRNAs. Whereas LIN28A and downregulated let-7s individually de-repress c-Myb-mediated cisplatin resistance, the ectopic expression of let-7s attenuates LIN28A effects, thus underlying a c-Myb-NKILA-LIN28A-let-7 axis in cisplatin resistance of ovarian cancer cells that needs to be further explored for therapeutic intervention.

SRSF1 induces glioma progression and has a potential diagnostic application in grading primary glioma

Glioma is the most common intracranial tumor of the central nervous system in adults; however, the diagnosis of glioma, and its grading and histological subtyping, is challenging for pathologists. The present study assessed serine and arginine rich splicing factor 1 (SRSF1) expression in 224 glioma cases in the Chinese Glioma Genome Atlas (CGGA) database, and verified its expression by immunohistochemical analysis of specimens from 70 clinical patients. In addition, the prognostic potential of SRSF1 concerning the survival status of patients was evaluated. In vitro, the biological role of SRSF1 was assessed using MTT, colony formation, wound healing and Transwell assays. The results revealed that SRSF1 expression was significantly associated with the grading and the histopathological subtype of glioma. As determined using a receiver operating characteristic curve analysis, the specificity of SRSF1 for glioblastoma (GBM) and World Health Organization (WHO) grade 3 astrocytoma was 40 and 48%, respectively, whereas the sensitivity was 100 and 85%. By contrast, pilocytic astrocytoma tumors exhibited negative immunoexpression of SRSF1. Additionally, Kaplan-Meier survival analysis indicated that high SRSF1 expression predicted a worse prognosis for patients with glioma in both the CGGA and clinical cohorts. In vitro, the results demonstrated that SRSF1 promoted the proliferation, invasion and migration of U87MG and U251 cells. These data suggested that immunohistochemical analysis of SRSF1 expression is highly sensitive and specific in the diagnosis of GBM and WHO grade 3 astrocytoma, and may have an important role in glioma grading. Furthermore, the lack of SRSF1 is a potential diagnostic biomarker for pilocytic astrocytoma. However, neither in oligodendroglioma and astrocytoma, nor in GBM was an association detected between SRSF1 expression and IDH1 mutations or 1p/19q co-deletion. These findings indicated that SRSF1 may serve as a prognostic factor in glioma cases and could have an active role in promoting glioma progression.

Long noncoding RNAs as therapeutic targets to overcome chemoresistance in ovarian cancer

Long noncoding RNAs (lncRNAs) have been characterized to play an essential role in ovarian tumorigenesis via controlling a variety of cellular processes, such as cell proliferation, invasion, apoptotic death, metastasis, cell cycle, migration, metabolism, immune evasion, and chemoresistance. The one obstacle for the therapeutic efficacy is due to the development of drug resistance in ovarian cancer patients. Therefore, in this review article, we describe the role of lncRNAs in chemoresistance in ovarian cancer. Moreover, we discuss the molecular mechanism of lncRNAs-involved drug resistance in ovarian cancer. We conclude that lncRNAs could be useful targets to overcome chemoresistance and improve therapeutic outcome in ovarian cancer patients.