Clinical and Prognostic Implications of P21 (WAF1/CIP1) Expression in Patients with Esophageal Cancer: A Systematic Review and Meta-Analysis

PLCD3 promotes malignant cell behaviors in esophageal squamous cell carcinoma via the PI3K/AKT/P21 signaling

BACKGROUND

Phospholipase C Delta 3 (PLCD3) is a member of phospholipase C(PLC) Protein and PLCD3 protein plays a prominent role in many cancers. However, little is known about the role of PLCD3 in esophageal squamous cell carcinoma (ESCC).

MATERIAL AND METHODS

We analyzed PLCD3 mRNA and protein expression in ESCC tissues and cell lines by immunohistochemistry, quantitative real-time PCR, and western blot. The correlation between PLCD3 expression and clinicopathological characteristics was also analyzed. CCK8, colony formation, wound-healing, and transwell assays were conducted to measure cell functional alternations. Flow cytometry was performed to assess the apoptosis rate and cell cycle caused by PLCD3 knockdown. Xenograft models in nude mice to clarify the role of PLCD3 in ESCC. Key proteins in the PI3K / AKT signaling pathway after treatment of ECA109 and KYSE150 cells with the AKT inhibitor MK2206 were analyzed by western blot.

RESULTS

PLCD3 was highly expressed in ESCC tissues and cell lines. PLCD3 expression levels correlated with pathologic stage and lymphatic metastasis. PLCD3 knockdown inhibited cell proliferation, migration, invasion, promoted apoptosis, and caused the cell cycle arrest in the G1 phase. PLCD3 overexpression promoted cell proliferation, migration, and invasion. In vivo experiments with xenografts demonstrated that PLCD3 promoted ESCC tumorigenesis. Finally, Overexpression of PLCD3 activated the PI3K / AKT / P21 signaling.

CONCLUSION

PLCD3 promotes malignant cell behaviors in esophageal squamous cell carcinoma via the PI3K/AKT/P21 signaling and could serve as a potential target for ESCC treatment.

Polymorphism at codon 31 of CDKN1A (p21) as a predictive factor for bevacizumab therapy in glioblastoma multiforme

Glioblastoma (GBM), a prevalent and malignant brain tumor, poses a challenge in surgical resection due to its invasive nature within the brain parenchyma. CDKN1A (p21, Waf-1), a cyclin-dependent kinase inhibitor, plays a pivotal role in regulating cell growth arrest, terminal differentiation, and apoptosis. The existence of natural variants of CDKN1A has been associated with specific cancer types. In this retrospective study, our objective was to identify polymorphic variants of CDKN1A, specifically c.93C > A (codon 31 Ser31Arg), and investigate its potential impact within the scope of bevacizumab therapy for glioblastoma multiforme. This study involved a cohort of 139 unrelated adult Chinese GBM patients in Taiwan. Genomic DNA extracted from tumor samples was utilized for genotyping using the polymerase chain reaction (PCR) restriction fragment length polymorphism method (PCR-RFLP analysis). Through unconditional logistic regression analysis, odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. Our findings unveiled that among these GBM patients, the distribution of codon 31 polymorphisms was as follows: 23.02% were Serine homozygotes (Ser/Ser), 27.34% were Arginine homozygotes (Arg/Arg), and 49.64% were Serine/Arginine heterozygotes (Ser/Arg). While CDKN1A c.93C > A polymorphisms did not exhibit a direct association with overall survival in GBM patients, noteworthy survival benefits emerged among individuals with Arg/Arg and Arg/Ser genotypes who received combined concurrent chemoradiotherapy (CCRT) and bevacizumab treatment compared to those who underwent CCRT alone. Our findings indicate a significant involvement of the CDKN1A c.93C > A polymorphism in the development and onset of GBM, offering potential implications for the early prognostication of bevacizumab therapy outcomes.

CRISPR-Cas13-Mediated Knockdown of lncRNA-GACAT3 Inhibited Cell Proliferation and Motility, and Induced Apoptosis by Increasing p21, Bax, and E-Cadherin Expression in Bladder Cancer

The current study is to investigate the expression pattern and biological function of long non-coding RNA Focally gastric cancer-associated transcript3 (GACAT3) in bladder cancer. Real-time quantitative qPCR was used to detect the expression level of GACAT-3 in tumor tissues and paired normal tissues. Human bladder cancer T24 and 5637 cell lines were transiently transfected with specific CRISPR-Cas13 or negative control CRISPR-Cas13. Cell migration, proliferation, and apoptosis were measured by using wound healing assay CCK-8 assay and Caspase-3 ELISA assay, respectively. The expression changes of p21, Bax, and E-cadherin after knockdown of GACAT3 were detected by using Western blot. The results demonstrated that GACAT3 was up-regulated in bladder cancer tissues than that in the paired normal tissues. Inhibition of cell proliferation, increased apoptosis, and decreased motility were observed in T24 and 5637 cell lines transfected by CRISPR-Cas13 targeting GACAT3. Downregulation of GACAT3 increased p21, Bax, and E-cadherin expression and silencing these genes could eliminate the phenotypic changes induced by knockdown of GACAT3. A ceRNA mechanism for GACAT3 was also revealed. By using CRISPR-Cas13 biotechnology, we suggested that GACAT3 may be a novel target for diagnosis and treatment of bladder cancer.

Function of p21 and its therapeutic effects in esophageal cancer

Esophageal cancer (EC) is the eighth most common type of cancer worldwide and ranks sixth among the causes of cancer-related mortality. Due to the high mortality rate and poor treatment efficacy for EC, millions of individuals succumb to this disease; thus, the identification of novel treatment targets is of utmost importance and urgency. In recent years, there have been advances if therapies targeting cell cycle regulators. p21 is a type of cell cycle regulator that plays a dual role in tumor cells, as it can not only regulate the cell cycle, induce apoptosis and inhibit cell proliferation, but can also protect cells from apoptosis. It has been found that p21 often exerts a tumor-suppressive effect on EC, which provides a basis for its use as a treatment target for EC. Therefore, the aim of the present study was to review the function of p21 and its potential value as a therapeutic target for EC.

The Role of Cell Cycle Regulators in Cell Survival-Dual Functions of Cyclin-Dependent Kinase 20 and p21Cip1/Waf1

The mammalian cell cycle is important in controlling normal cell proliferation and the development of various diseases. Cell cycle checkpoints are well regulated by both activators and inhibitors to avoid cell growth disorder and cancerogenesis. Cyclin dependent kinase 20 (CDK20) and p21^Cip1/Waf1 are widely recognized as key regulators of cell cycle checkpoints controlling cell proliferation/growth and involving in developing multiple cancers. Emerging evidence demonstrates that these two cell cycle regulators also play an essential role in promoting cell survival independent of the cell cycle, particularly in those cells with a limited capability of proliferation, such as cardiomyocytes. These findings bring new insights into understanding cytoprotection in these tissues. Here, we summarize the new progress of the studies on these two molecules in regulating cell cycle/growth, and their new roles in cell survival by inhibiting various cell death mechanisms. We also outline their potential implications in cancerogenesis and protection in heart diseases. This information renews the knowledge in molecular natures and cellular functions of these regulators, leading to a better understanding of the pathogenesis of the associated diseases and the discovery of new therapeutic strategies.

Overexpression of Rab40b Promotes Hepatocellular Carcinoma Cell Proliferation and Metastasis via PI3K/AKT Signaling Pathway

Background

Rab40b is an evolutionarily conserved Rab GTPase that plays an important role in intracellular trafficking and is closely related to cancer progression. However, the role and potential molecular mechanism of Rab40b in hepatocellular carcinoma (HCC) have not yet been elucidated.

Materials and Methods

The expression of Rab40b in HCC tissues and peritumour tissues was tested by qRT-PCR, Western blotting and histological analysis. A Kaplan-Meier survival curve was generated based on the expression of Rab40b in the HCC samples. Cell proliferation assays, wound healing assays, and transwell assays are used to examine the effect of Rab40b on HCC cell growth in vitro. The effect of Rab40b on cell cycle was examined by flow cytometry. A xenograft implantation model was used to assess the effect of Rab40b on the development of HCC cells in vivo.

Results

Rab40b protein expression is upregulated in HCC tissues, and this upregulation is associated with high pathological stage and poor prognosis in HCC patients. Rab40b overexpression promotes the proliferation and metastasis of HCC cells by upregulating cyclin D1, cyclin E1 and matrix metalloproteinase 2 (MMP2) through the PI3K/AKT signalling pathway. Conversely, Rab40b inhibitors can significantly inhibit the proliferation and metastasis of HCC cell lines and induce G0/G1 cell cycle arrest and apoptosis. Studies of a nude mouse xenograft model demonstrated that Rab40b knockdown can significantly inhibit the proliferation and progression of HCC tumours in vivo.

Conclusion

Overall, this study demonstrates that Rab40b is an important oncoprotein that promotes HCC progression by regulating the expression of cyclin D1, cyclin E1, p21 and MMP2 through the PI3K/AKT signalling pathway.