Cellular Oncology最新文献

Purpose: Cancer cells are characterized as the uncontrolled proliferation, which demands high levels of nucleotides that are building blocks for DNA synthesis and replication. CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase and dihydroorotase) is a trifunctional enzyme that initiates the de novo pyrimidine synthesis, which is normally enhanced in cancer cells to preserve the pyrimidine pool for cell division. Glioma, representing most brain cancer, is highly addicted to nucleotides like pyrimidine to sustain the abnormal growth and proliferation of cells. CAD is previously reported to be dysregulated in glioma, but the underlying mechanism remains unclear.

Methods: The expression of CAD and CHIP (carboxyl terminus of Hsc70-interacting protein) protein in normal brain cells and three glioblastoma (GBM) cell lines were measured by immunoblots. Lentiviruses-mediated expression of target proteins or shRNAs were used to specifically overexpress or knock down CAD and CHIP. Cell counting, colony formation, apoptosis and cell cycle assays were used to assess the roles of CAD and CHIP in GBM cell proliferation and survival. Co-immunoprecipitation and ubiquitination assays were used to examine the interaction of CHIP with CAD and the ubiquitination of CAD. The correlation of CAD and CHIP expression with GBM patients' survival was obtained by analyzing the GlioVis database.

Results: In this study, we showed that the expression of CAD was upregulated in glioma, which was positively correlated with the tumor grade and survival of glioma patients. Knockdown of CAD robustly inhibited the cell proliferation and colony formation of GBM cells, indicating the essential role of CAD in the pathogenesis of GBM. Mechanistically, we firstly identified that CAD was modified by the K29-linked polyubiquitination, which was mediated by the E3 ubiquitin ligase CHIP. By interacting with and ubiquitinating CAD, CHIP enhanced its proteasomal and lysosomal degradation, which accounted for the anti-proliferative role of CHIP in GBM cells. To sustain the expression of CAD, CHIP is significantly downregulated, which is correlated with the poor prognosis and survival of GBM patients. Notably, the low level of CHIP and high level of CAD overall predict the short survival of GBM patients.

Conclusion: Altogether, these results illustrated the essential role of CAD in GBM and revealed a novel therapeutic strategy for CAD-positive and CHIP-negative cancer.

Purpose: PiwiL1 has been reported to be over-expressed in many cancers. However, the molecular mechanism by which these proteins contribute to tumorigenesis and their regulation in cancer cells is still unclear. We intend to understand the role of PiwiL1 in tumorigenesis and also its regulation in cervical cells.

Methods: We studied the effect of loss of PiwiL1 function on tumor properties of cervical cancer cells in vitro and in vivo. Also we have looked into the effect of PiwiL1 overexpression in the malignant transformation of normal cells both in vitro and in vivo. Further RNA-seq and RIP-seq analyses were done to get insight of the direct and indirect targets of PiwiL1 in the cervical cancer cells.

Results: Here, we report that PiwiL1 is not only over-expressed, but also play a major role in tumor induction and progression. Abolition of PiwiL1 in CaSki cells led to a decrease in the tumor-associated properties, whereas, its upregulation conferred malignant transformation of normal HaCaT cells. Our study delineates a new link between HPV oncogenes, E6 and E7 with PiwiL1. p53 and E2F1 directly bind and differentially regulate PiwiL1 promoter in a context-dependant manner. Further, RNA-seq together with RIP-RNA-seq suggested a strong and direct role for PiwiL1 in promoting metastasis in cervical cancer cells.

Conclusion: Our study demonstrates that PiwiL1 act as an oncogene in cervical cancer by inducing tumor-associated properties and EMT pathway. The finding that HPV oncogenes, E6/E7 can positively regulate PiwiL1 suggests a possible mechanism behind HPV-mediated tumorigenesis in cervical cancer.

Background: Vulvar squamous cell carcinoma (VSCC) is a rare disease with a poor prognosis. To date, there's no proper in vitro modeling system for VSCC to study its pathogenesis or for drug evaluation.

Methods: We established healthy vulvar (HV)- and VSCC-like 3D full thickness models (FTMs) to observe the tumor-stroma interaction and their applicability for chemotherapeutic efficacy examination. VSCC-FTMs were developed by seeding VSCC tumor cell lines (A431 and HTB117) onto dermal matrices harboring two NF subtypes namely papillary fibroblasts (PFs) and reticular fibroblasts (RFs), or cancer-associated fibroblasts (CAFs) while HV-FTMs were constructed with primary keratinocytes and fibroblasts isolated from HV tissues.

Results: HV-FTMs highly resembled HV tissues in terms of epidermal morphogenesis, basement membrane formation and collagen deposition. When the dermal compartment shifted from PFs to RFs or CAFs in VSCC-FTMs, tumor cells demonstrated more proliferation, EMT induction and stemness. In contrast to PFs, RFs started to lose their phenotype and express robust CAF-markers α-SMA and COL11A1 under tumor cell signaling induction, indicating a favored 'RF-to-CAF' transition in VSCC tumor microenvironment (TME). Additionally, chemotherapeutic treatment with carboplatin and paclitaxel resulted in a significant reduction in tumor-load and invasion in VSCC-FTMs.

Conclusion: We successfully developed in vitro 3D vulvar models mimicking both healthy and tumorous conditions which serve as a promising tool for vulvar drug screening programs. Moreover, healthy fibroblasts demonstrate heterogeneity in terms of CAF-activation in VSCC TME which brings insights in the future development of novel CAF-based therapeutic strategies in VSCC.

Background

Lung adenocarcinoma (LUAD) is the most common histological type of lung cancer with lower survival rates. Recent advancements in targeted therapies and immunotherapies targeting immune checkpoints have achieved remarkable success, there is still a large percentage of LUAD that lacks available therapeutic options. Due to tumor heterogeneity, the diagnosis and treatment of LUAD are challenging. Exploring the biology of LUAD and identifying new biomarker and therapeutic targets options are essential.

Method

We performed single-cell RNA sequencing (scRNA-seq) of 6 paired primary and adjacent LUAD tissues, and integrative omics analysis of the scRNA-seq, bulk RNA-seq and whole-exome sequencing data revealed molecular subtype characteristics. Our experimental results confirm that CDC25C gene can serve as a potential marker for poor prognosis in LUAD.

Results

We investigated aberrant gene expression in diverse cell types in LUAD via the scRNA-seq data. Moreover, multi-omics clustering revealed four subgroups defined by transcriptional profile and molecular subtype 4 (MS4) with poor survival probability, and immune cell infiltration signatures revealed that MS4 tended to be the immunosuppressive subtype. Our study revealed that the CDC25C gene can be a distinct prognostic biomarker that indicates immune infiltration levels and response to immunotherapy in LUAD patients. Our experimental results concluded that CDC25C expression affects lung cancer cell invasion and migration, might play a key role in regulating Epithelial-Mesenchymal Transition (EMT) pathways.

Conclusions

Our multi-omics result revealed a comprehensive set of molecular attributes associated with prognosis-related genes in LUAD at the cellular and tissue level. Identification of a subtype of immunosuppressive TME and prognostic signature for LUAD. We identified the cell cycle regulation gene CDC25C affects lung cancer cell invasion and migration, which can be used as a potential biomarker for LUAD.