lncRNA ZFAS1 Promotes HMGCR mRNA Stabilization via Binding U2AF2 to Modulate Pancreatic Carcinoma Lipometabolism

LncRNA SNHG14 Facilitates Cisplatin Resistance Through Upregulating Notch2 via Binding to U2AF2 in Nasopharyngeal Carcinoma

BACKGROUND

Cisplatin (DDP) is one of the commonly used chemotherapeutic drugs for nasopharyngeal carcinoma (NPC) patients, and the resistance of tumor cells to cisplatin is main obstacle for NPC treatment. This study explored effect and possible mechanism of lncRNA small nucleolar RNA host gene 14 (SNHG14) on drug resistance of NPC cells to cisplatin.

METHODS

Levels of SNHG14 and Notch2 in NPC tissues and cells were confirmed using RT-qPCR. Western blot detected Notch2 and ABCB1 expression in NPC cells. IC50 of cisplatin-treated NPC cells was tested utilizing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Cell proliferation and apoptosis were evaluated utilizing colony formation experiment and flow cytometry, respectively. RNA immunoprecipitation (RIP) assay was utilized to validate the target genes of U2AF2. Notch2 mRNA stability was tested using actinomycin D.

RESULTS

SNHG14 level was increased in both cisplatin-resistant NPC tissues and cell lines. SNHG14 silencing in HNE1/DDP cells resulted in inhibition of chemoresistance to cisplatin. Conversely, upregulation of SNHG14 in HNE1 cells enhanced their resistance to cisplatin. SNHG14 exhibited an interaction with U2AF2, leading to stabilization of Notch2 mRNA. Finally, Notch2 was involved in SNHG14-mediated cisplatin resistance in NPC cells.

CONCLUSION

Our findings demonstrate SNHG14 plays a significant role in promoting chemoresistance of NPC cells to cisplatin through U2AF2/Notch2 axis. These results highlight potential therapeutic targets for NPC treatment.

The Expression Analysis of Long Non-coding RNAs Related to Wnt/β-Catenin Signaling in Pancreatic Cancer Patients

Background The oncogenic Wnt/β-catenin signaling plays a critical role in carcinogenesis, prognosis, and resistance to therapy. Pancreatic cancer (PC) has high mortality because of its poor prognosis. Several studies have suggested that lncRNAs are directly involved in the development and progression of PC as well as in Wnt/β-catenin signaling. In this study, we investigated and compared the expression of Wnt/β-catenin signaling-related ZFAS1 and HCG11 lncRNAs, and their targets, CTNNB1 and IGF2BP1 genes in the blood of patients with PC and healthy individuals. A total of 47 PC patients and 50 healthy individuals participated in this study. RNA was extracted from the peripheral blood samples of participants, and cDNA was synthesized. The expression level of the selected genes was quantified by real-time PCR. The expression of HCG11 lncRNA and CTNNB1 genes in patients with PC was significantly upregulated compared to healthy individuals, and the expression of the ZFAS1 lncRNA was significantly downregulated. According to the analysis of the ROC curve, the diagnostic powers of ZFAS1 and CTNNB1 in PC were 0.67 and 0.69, respectively. Altogether, the present study suggests a role for ZFAS1 and HCG11 lncRNAs and CTNNB1 and IGF2BP1 in the pathogenesis of pancreatic cancer. Moreover, the peripheral expression of these lncRNAs may be useful as potential biomarkers for PC.

The role of lncRNA binding to RNA‑binding proteins to regulate mRNA stability in cancer progression and drug resistance mechanisms (Review)

Cancer is a disease that poses a serious threat to human health, the occurrence and development of which involves complex molecular mechanisms. Long non‑coding RNAs (lncRNAs) and RNA‑binding proteins (RBPs) are important regulatory molecules within cells, which have garnered extensive attention in cancer research in recent years. The binding of lncRNAs and RBPs plays a crucial role in the post‑transcriptional regulation of mRNA, affecting the synthesis of proteins related to cancer by regulating the stability of mRNA. This, in turn, regulates the malignant biological behaviors of tumor cells, such as proliferation and metastasis, and serves an important role in therapeutic resistance. The present study reviewed the role of lncRNA‑RBP interactions in the regulation of mRNA stability in various malignant tumors, with a focus on the molecular mechanisms underlying this regulatory interaction. The aim of the present review was to gain a deeper understanding of these molecular mechanisms to provide new strategies and insights for the precise treatment of cancer.

De novo lipid synthesis and polarized prenylation drive cell invasion through basement membrane

To breach the basement membrane, cells in development and cancer use large, transient, specialized lipid-rich membrane protrusions. Using live imaging, endogenous protein tagging, and cell-specific RNAi during Caenorhabditis elegans anchor cell (AC) invasion, we demonstrate that the lipogenic SREBP transcription factor SBP-1 drives the expression of the fatty acid synthesis enzymes POD-2 and FASN-1 prior to invasion. We show that phospholipid-producing LPIN-1 and sphingomyelin synthase SMS-1, which use fatty acids as substrates, produce lysosome stores that build the AC's invasive protrusion, and that SMS-1 also promotes protrusion localization of the lipid raft partitioning ZMP-1 matrix metalloproteinase. Finally, we discover that HMG-CoA reductase HMGR-1, which generates isoprenoids for prenylation, localizes to the ER and enriches in peroxisomes at the AC invasive front, and that the final transmembrane prenylation enzyme, ICMT-1, localizes to endoplasmic reticulum exit sites that dynamically polarize to deliver prenylated GTPases for protrusion formation. Together, these results reveal a collaboration between lipogenesis and a polarized lipid prenylation system that drives invasive protrusion formation.

An update on the molecular mechanisms of ZFAS1 as a prognostic, diagnostic, or therapeutic biomarker in cancers

Zinc finger antisense 1 (ZFAS1), a newly discovered long noncoding RNA, is expressed in various tissues and organs and has been introduced an oncogenic gene in human malignancies. In various cancers, ZFAS1 regulates apoptosis, cell proliferation, the cell cycle, migration, translation, rRNA processing, and spliceosomal snRNP assembly; targets signaling cascades; and interacts with transcription factors via binding to key proteins and miRNAs, with conflicting findings on its effect on these processes. ZFAS1 is elevated in different types of cancer, like colorectal, colon, osteosarcoma, and gastric cancer. Considering the ZFAS1 expression pattern, it also has the potential to be a diagnostic or prognostic marker in various cancers. The current review discusses the mode of action of ZFAS1 in various human cancers and its regulation function related to chemoresistance comprehensively, as well as the potential role of ZFAS1 as an effective and noninvasive cancer-specific biomarker in tumor diagnosis, prognosis, and treatment. We expected that the current review could fill the current scientific gaps in the ZFAS1-related cancer causative mechanisms and improve available biomarkers.

Long Non-Coding RNAs and Metabolic Rewiring in Pancreatic Cancer

Pancreatic adenocarcinoma is a highly aggressive disease with a poor prognosis. The reprogramming of energetic metabolism has long been implicated in pancreatic tumorigenesis and/or resistance to treatment. Considering that long non-coding RNA dysregulation has been described both in cancerogenesis and in the altered homeostasis of several metabolic pathways, metabolism-associated lncRNAs can contribute to pancreatic cancer evolution. The objective of this review is to assess the burden of lncRNA dysregulation in pancreatic cancer metabolic reprogramming, and its effect on this tumor's natural course and response to treatment. Therefore, we reviewed the available literature to assess whether metabolism-associated lncRNAs have been found to be differentially expressed in pancreatic cancer, as well as whether experimental evidence of their role in such pathways can be demonstrated. Specifically, we provide a comprehensive overview of lncRNAs that are implicated in hypoxia-related pathways, as well as in the reprogramming of autophagy, lipid metabolism, and amino acid metabolism. Our review gathers background material for further research on possible applications of metabolism-associated lncRNAs as diagnostic/prognostic biomarkers and/or as potential therapeutic targets in pancreatic adenocarcinoma.

SIAH1 ubiquitination-modified HMGCR inhibits lung cancer progression and promotes drug sensitivity through cholesterol synthesis

BACKGROUNDS

Lung cancer is one of the most frequently diagnosed cancers and the leading cause of cancer-related deaths worldwide. Deep understanding of chemoresistance will lead to remarkable progress in lung cancer treatment strategy. Cholesterol accumulation was associated with cisplatin resistance in lung cancer treatment. And we found the degree of cisplatin resistance was correlated with the expression of the cholesterol synthesis HMGCR.

METHODS

We analyzed a group of 42 lung cancer patients who received cisplatin treatment after lung resection surgery. The expression of HMGCR and its correlation with cholesterol in lung cancer cell lines were determined by qRT-PCR and ELISA analyses. We focus on the function and mechanism of HMGCR in lung cancer and reveal that knockdown of HMGCR expression inhibits the proliferation, colony formation, and migration of lung cancer cell lines in vitro or in vivo and dramatically enhances the efficacy of cisplatin.

RESULTS

Through mechanism studies, we illustrate that SIAH1, an E3 ubiquitin-protein ligase, ubiquitination modifies HMGCR and inhibits efflux protein activity via regulating cholesterol synthesis. In vivo experiments showed that SIAH1 overexpression or using HMGCR knockdown retard tumor growth and enhanced the efficacy of cisplatin. In summary, HMGCR affects cholesterol metabolism by regulating key enzymes in cholesterol synthesis, thereby reducing drug sensitivity.

CONCLUSION

This study indicates that lung cancer patients with lower HMGCR levels may lead to a better prognosis and provide a potential treatment by SIAH1 overexpression for lung cancer patients with cisplatin resistance.