In silico analysis of DYNLL1 expression in ovarian cancer chemoresistance

DYNLL1 accelerates cell cycle via ILF2/CDK4 axis to promote hepatocellular carcinoma development and palbociclib sensitivity

BACKGROUND

Disorder of cell cycle represents as a major driver of hepatocarcinogenesis and constitutes an attractive therapeutic target. However, identifying key genes that respond to cell cycle-dependent treatments still facing critical challenges in hepatocellular carcinoma (HCC). Increasing evidence indicates that dynein light chain 1 (DYNLL1) is closely related to cell cycle progression and plays a critical role in tumorigenesis. In this study, we explored the role of DYNLL1 in the regulation of cell cycle progression in HCC.

METHODS

We analysed clinical specimens to assess the expression and predictive value of DYNLL1 in HCC. The oncogenic role of DYNLL1 was determined by gain or loss-of-function experiments in vitro, and xenograft tumour, liver orthotopic, and DEN/CCl4-induced mouse models in vivo. Mass spectrometry analysis, RNA sequencing, co-immunoprecipitation assays, and forward and reverse experiments were performed to clarify the mechanism by which DYNLL1 activates the interleukin-2 enhancer-binding factor 2 (ILF2)/CDK4 signalling axis. Finally, the sensitivity of HCC cells to palbociclib and sorafenib was assessed by apoptosis, cell counting kit-8, and colony formation assays in vitro, and xenograft tumour models and liver orthotopic models in vivo.

RESULTS

DYNLL1 was significantly higher in HCC tissues than that in normal liver tissues and closely related to the clinicopathological features and prognosis of patients with HCC. Importantly, DYNLL1 was identified as a novel hepatocarcinogenesis gene from both in vitro and in vivo evidence. Mechanistically, DYNLL1 could interact with ILF2 and facilitate the expression of ILF2, then ILF2 could interact with CDK4 mRNA and delay its degradation, which in turn activates downstream G1/S cell cycle target genes CDK4. Furthermore, palbociclib, a selective CDK4/6 inhibitor, represents as a promising therapeutic strategy for DYNLL1-overexpressed HCC, alone or particularly in combination with sorafenib.

CONCLUSIONS

Our work uncovers a novel function of DYNLL1 in orchestrating cell cycle to promote HCC development and suggests a potential synergy of CDK4/6 inhibitor and sorafenib for the treatment of HCC patients, especially those with increased DYNLL1.

Retinoic acid mitigates the NSC319726-induced spermatogenesis dysfunction through cuproptosis-independent mechanisms

Copper ionophore NSC319726 has attracted researchers' attention in treating diseases, particularly cancers. However, its potential effects on male reproduction during medication are unclear. This study aimed to determine whether NSC319726 exposure affected the male reproductive system. The reproductive toxicity of NSC319726 was evaluated in male mice following a continuous exposure period of 5 weeks. The result showed that NSC319726 exposure caused testis index reduction, spermatogenesis dysfunction, and architectural damage in the testis and epididymis. The exposure interfered with spermatogonia proliferation, meiosis initiation, sperm count, and sperm morphology. The exposure also disturbed androgen synthesis and blood testis barrier integrity. NSC319726 treatment could elevate the copper ions in the testis to induce cuproptosis in the testis. Copper chelator rescued the elevated copper ions in the testis and partly restored the spermatogenesis dysfunction caused by NSC319726. NSC319726 treatment also decreased the level of retinol dehydrogenase 10 (RDH10), thereby inhibiting the conversion of retinol to retinoic acid, causing the inability to initiate meiosis. Retinoic acid treatment could rescue the meiotic initiation and spermatogenesis while not affecting the intracellular copper ion levels. The study provided an insight into the bio-safety of NSC319726. Retinoic acid could be a potential therapy for spermatogenesis impairment in patients undergoing treatment with NSC319726.

Estrogen- and estrogen receptor (ER)-mediated cisplatin chemoresistance in cancer

Cisplatin is a platinum-based chemotherapeutic drug used in the standard treatment of various solid cancers including testicular, bladder, head and neck, cervical and ovarian cancer. Although successful clinical responses are observed in patients following initial cisplatin treatment, resistance to cisplatin ultimately develops in most patients, leading to therapeutic failure. Multiple molecular mechanisms contributing to cisplatin resistance in cancer cells have been identified to date. In this review, we discuss the effect of estrogen, estrogen receptors (ERs) and estrogen-related receptors (ERRs) on cisplatin resistance in various cancer types. We highlight that estrogen treatment or increased expression of ERs or ERRs are generally associated with higher cisplatin resistance in cancer in vitro, mostly due to decreased caspase activity, increased anti-apoptotic protein levels such as BCL-2, higher drug efflux and higher levels of antioxidant enzymes. Targeted inhibition of ERs or estrogen production in combination with cisplatin treatment thus can be a useful strategy to overcome chemoresistance in certain cancer types. Estrogen levels and ER status can also be considered to identify cancer patients with a high potential of therapy response against cisplatin. A better mechanistic understanding of the involvement of estrogen, ERs and ERRs in the development of cisplatin resistance is needed to improve the management of cancer treatment.

Involvement of ATMIN-DYNLL1-MRN axis in the progression and aggressiveness of serous ovarian cancer

The loss of DYNLL1 contributes to chemoresistance in ovarian cancer. DYNLL1 binds to MRE11, a component of MRN complex (MRE11-RAD50-NBS1), and limits its function in homologous recombination (HR) repair in BRCA1-mutant cells. Decreased activity of MRE11 results in less HR-repair events and thus leads to higher sensitivity against DNA-damaging agents such as cisplatin. Therefore, a better understanding of the cellular changes in DYNLL1-MRN axis in ovarian cancer is needed. Here, we showed that DYNLL1 overexpression leads to decreased chemoresistance even in BRCA-proficient ovarian cancer cells. ATMIN, a transcriptional activator of DYNLL1, showed decreased expression; however, two components of MRN complex, MRE11 and NBS1 (NBN), showed increased expression in high grade compared to low grade serous ovarian cancer. We found that the components of MRN complex (MRE11-RAD50-NBS1) have higher protein levels in sites of omental metastasis and serous tubal intraepithelial carcinoma (STIC) compared to surrounding non-malignant stromal cells in patients with high grade serous ovarian cancer. We showed that the percentage of copy number variation (CNV) events in genes encoding ATMIN, DYNLL1, MRE11 and NBN are the highest in ovarian cancer among other cancer types. ATMIN and DYNLL1 genes are mostly characterized by copy number losses; however, CNV events in MRN complex components are mostly copy number gains. This study highlights the importance of ATMIN-DYNLL1-MRN axis in the development, progression and therapy response of ovarian cancer. MRN levels in ovarian cancer that differ from adjacent, non-malignant tissues may represent actionable therapeutic vulnerabilities.

A Novel miRNA-mRNA Axis Involves in Regulating Transcriptional Disorders in Pancreatic Adenocarcinoma

Background

Currently, there is still a lack of understanding about the mechanism and therapeutic targets of pancreatic adenocarcinoma (PAAD). The potential of miRNA-mRNA networks for the identification of regulatory mechanisms involved in PAAD development remains unexplored.

Methods

We compared differentially expressed miRNAs (DEMIs) and differentially expressed genes (DEGs) in PAAD and normal tissues from the Gene Expression Omnibus (GEO) database. Transcription factors (TFs) were obtained from FunRich. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs and DEMIs were implemented using Database for Annotation, Visualization and Integrated Discovery (DAVID). Then, key miRNAs and targeted mRNAs were identified by assessment of their expression and prognosis in UALCAN and Kaplan-Meier plotters. In the last step, the candidate miRNA-mRNA selected was confirmed by real-time quantitative polymerase chain reaction (qRT-PCR).

Results

We distinguished 62 significant DEMIs, 1314 upregulated DEGs, and 1110 downregulated DEGs. The top 10 TFs were identified. In total, there were 160 hub genes obtained by intersecting the set of 2224 predicted targets with the set of significant DEGs. And we selected 8 key miRNAs. Furthermore, low expression of miR-455-3p in PAAD tissue was closely connected with poor prognosis, and only 5 target mRNAs were predicted to be increased in PAAD tissue with poor prognosis. Therefore, a novel miRNA-hub gene regulatory network in PAAD was constructed. Finally, in vitro experiments indicated that miR-455-3p expression was decreased in PAAD sample. HOXC4, DLG4, DYNLL1 and FBXO45 were validated by qRT-PCR as highly probable targets of miR-455-3p.

Conclusion

A novel miRNA-mRNA axis has been discovered that may be involved in the regulation of transcriptional disorders and affected the survival of PAAD patients, which would provide a novel strategy for the treatment of PAAD.

Transcriptomic analysis reveals tumor stage- or grade-dependent expression of miRNAs in serous ovarian cancer

Ovarian cancer (OC) is the most lethal gynecological malignancy and cellular mechanisms regulating OC progression are not completely understood. miRNAs are involved in many signaling pathways which are critical for the progression of malignant tumors, including OC. In the present study, we aim to identify miRNAs whose expression change in a tumor stage- and/or grade-dependent manner in serous OC. Computational analysis was performed in R using The Cancer Genome Atlas miRNA dataset. Kaplan-Meier plots were constructed to compare the survival of patients with low and high expressions of identified miRNAs. We found that 91 and 90 miRNAs out of 799 are differentially expressed in terms of tumor stage and grade, respectively. miR-152, miR-375 and miR-204 were top three hits in terms of tumor stage; and similarly, miR-125b, miR-768-5p and -3p in terms of tumor grade. Among top 15 miRNAs whose expression most significantly changed between tumor stages, 66.7% were upregulated in late stage. However, 53.3% of top 15 miRNAs identified in terms of tumor grade were upregulated in high grade. 11 miRNAs are differentially expressed in terms of both tumor stage and grade. Expression changes of some of the top miRNAs were found to be associated with shorter survival in serous OC. Text mining analysis showed that most of these miRNAs have not been previously studied in the context of OC. Mechanistic studies of these miRNAs in OC progression, differentiation and metastasis will be of high importance to develop novel strategies for the treatment of serous ovarian cancer.

DYNLL1 is hypomethylated and upregulated in a tumor stage- and grade-dependent manner and associated with increased mortality in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and cellular mechanisms regulating HCC pathogenesis and progression are not completely understood. DYNLL1 is essential for the development and expansion of MYC-driven B cell lymphoma, and also regulates genomic stability and responses to DNA-damaging chemotherapy in BRCA1-deficient tumors. However, the role and regulation of DYNLL1 has not been previously studied in the context of HCC. Here we report that DYNLL1 gene is hypomethylated and its expression is upregulated in HCC patients compared to healthy controls. The expression of DYNLL1 changes in a tumor grade- and stage-dependent manner in HCC. In this study, we further show that high DYNLL1 expression results in shorter overall and progression-free survival in hepatocellular carcinoma patients. Similar to DYNLL1, one of its protein interactors, RACK1, also shows decreased CpG-aggregated methylation and increased expression in HCC. RACK1 expression increases from early to late stage and from low to high grade in HCC. We found that high RACK1 expression is significantly associated with increased mortality of HCC patients. The present study shows that the epigenetic regulation of DYNLL1 and its consequent upregulation might be contributing to cancer development and progression in HCC. Its higher expression in late stage or high grade HCC may favor more aggressive disease as pointed by the increased mortality in high expression cohort. A better mechanistic understanding of the role of DYNLL1 in HCC will be needed to develop targeted treatment strategies in the future.

GAB2 and GAB3 are expressed in a tumor stage-, grade- and histotype-dependent manner and are associated with shorter progression-free survival in ovarian cancer

Ovarian cancer is the most lethal gynecological malignancy and molecular mechanisms of its progression and metastasis are not completely understood. Some members of GAB (GRB2-associated binding) protein family have been reported to be involved in tumor cell proliferation and metastasis in various cancer types. In the present study, we analyzed the expression of GAB proteins (GAB1, GAB2 and GAB3) in ovarian cancer compared to normal ovarian tissue, in terms of tumor stage, tumor grade and histological type. Differential expression analyses performed in R programming environment using multiple transcriptome datasets (n = 1449) showed that GAB1 expression is decreased in ovarian cancer independently of tumor stage, grade and histotype. Unlike GAB1, expression of GAB2 and GAB3 are increased from early stage to late stage and from low grade to high grade in epithelial ovarian cancer. GAB2 and GAB3 also showed histotype-dependent expression. GAB3 was computed as a top gene whose expression most significantly changed between tumor cells from primary tumor, metastases and ascites. High expression of GAB2 and GAB3 was shown to be associated with shorter progression-free survival in ovarian cancer. This study shows that GAB2 and GAB3 can be important regulators of tumor progression and metastasis in ovarian cancer.