GAS2-Calpain2 axis contributes to the growth of leukemic cells

Terpinen-4-ol suppresses proliferation and motility of cutaneous squamous cell carcinoma cells by enhancing calpain-2 expression

Background

Terpinen-4-ol (T4O), a key constituent of tea tree essential oil and various aromatic plants, has shown promising antiproliferative and pro-apoptotic effects in melanoma and other cancer types. However, its efficacy against cutaneous squamous cell carcinoma (cSCC) remains unclear. Thus, in this study, we investigated the in vivo and in vitro effects of T4O on cSCC cell lines and preliminarily explored its impacting pathways.

Methods

Using CCK8 and assay colony formation, we assessed the viability of cSCC A431, SCL-1, and COLO-16 cells treated with T40 at varying concentrations (0, 1, 2, and 4 μM). Flow cytometry was employed to evaluate T4O's effect on cSCC cell's cycle progression and apoptosis induction. Additionally, western blotting was utilized to examine the expression intensities of N-cadherin and E-cadherin, two indicative markers of the epithelial-mesenchymal transition (EMT) pathway. T4O's in vivo effect on inhibiting tumor progression was evaluated on an established xenograft tumor model. Then, the molecular mechanisms of T4O's antitumor effect were explored by an integrated genome-wide transcriptomics and proteomics study on cSCC A431c cells. Finally, calpain-2's potential mediator role in T4O's anti-tumor mechanism was investigated in calpain-2 knockdown cell lines prepared via siRNA transfection.

Result

It's demonstrated that T4O treatment inhibited cSCC proliferation, clonogenicity, migration, and invasion while inducing apoptosis and suppressing the EMT pathway. T4O administration also inhibited cSCC tumorigenesis in the xenograft tumor model. RNA-sequencing and iTRAQ analysis detected significant upregulation of calpain-2 expression in T4O-treated cSCC cells. Western blotting confirmed that T4O significantly increased calpain-2 expression and promoted proteolytic cleavage of β-catenin and caspase-12, two calpain-2 target proteins. Importantly, siRNA-mediated calpain-2 knockdown relieved T4O's suppressive effect on cSCC cell proliferation and motility. Mechanistically, T4O upregulates calpain-2 expression and promotes the cleavage of β-catenin and caspase-12, with siRNA-mediated calpain-2 knockdown mitigating T4O's suppressive effects.

Conclusion

These findings suggest that T4O's antitumor activity in cSCC is mediated through the upregulation of calpain-2 expression and subsequent modulation of β-catenin and caspase-12.

A comprehensive analysis of GAS2 family members identifies that GAS2L1 is a novel biomarker and promotes the proliferation of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common primary liver cancer with a high incidence and mortality. Members of the growth-arresting-specific 2 (GAS2) family are involved in various biological processes in human malignancies. To date, there is only a limited amount of information available about the expression profile and clinical importance of GAS2 family in HCC. In this study, we found that GAS2L1 and GAS2L3 were distinctly upregulated in HCC specimens compared to non-tumor specimens. Pan-cancer assays indicated that GAS2L1 and GAS2L3 were highly expressed in most cancers. The Pearson's correlation revealed that the expressions of GAS2, GAS2L1 and GAS2L2 were negatively associated with methylation levels. Survival assays indicated that GAS2L1 and GAS2L3 were independent prognostic factors for HCC patients. Immune cell infiltration analysis revealed that GAS2, GAS2L1 and GAS2L3 were associated with several immune cells. Finally, we confirmed that GAS2L1 was highly expressed in HCC cells and its knockdown suppressed the proliferation of HCC cells. Taken together, our findings suggested the expression patterns and prognostic values of GAS2 members in HCC, providing insights for further study of the GAS2 family as sensitive diagnostic and prognostic markers for HCC.

Growth arrest‐specific protein 2 ( GAS2 ) interacts with CXCR4 to promote T‐cell leukemogenesis partially via c‐MYC

Although growth arrest‐specific protein 2 (GAS2) promotes the growth of T‐cell acute lymphoblastic leukemia (T‐ALL) cells in culture, the effect of GAS2 on T‐cell leukemogenesis has not been studied, and the mechanism remains unclear. In the present study, xenograft studies showed that GAS2 silencing impaired T‐cell leukemogenesis and decreased leukemic cell infiltration. Mechanistically, GAS2 regulated the protein expression of C‐X‐C chemokine receptor type 4 (CXCR4) rather than its transcript expression. Immunoprecipitation revealed that GAS2 interacted with CXCR4, and confocal analysis showed that GAS2 was partially co‐expressed with CXCR4, which provided a strong molecular basis for GAS2 to regulate CXCR4 expression. Importantly, CXCR4 overexpression alleviated the inhibitory effect of GAS2 silencing on the growth and migration of T‐ALL cells. Moreover, GAS2 or CXCR4 silencing inhibited the expression of NOTCH1 and c‐MYC. Forced expression of c‐MYC rescued the growth suppression induced by GAS2 or CXCR4 silencing. Meanwhile, GAS2 deficiency, specifically in blood cells, had a mild effect on normal hematopoiesis, including T‐cell development, and GAS2 silencing did not affect the growth of normal human CD3⁺ or CD34⁺ cells. Overall, our data indicate that GAS2 promotes T‐cell leukemogenesis through its interaction with CXCR4 to activate NOTCH1/c‐MYC, whereas impaired GAS2 expression has a mild effect on normal hematopoiesis. Therefore, our study suggests that targeting the GAS2/CXCR4 axis is a potential therapeutic strategy for T‐ALL.

Growth arrest-specific 2 protein family: Structure and function

Members of the growth arrest–specific 2 (GAS2) protein family consist of a putative actin‐binding (CH) domain and a microtubule‐binding (GAR) domain and are considered miniversions of spectraplakins. There are four members in the GAS2 family, viz. GAS2, GAS2L1, GAS2L2 and GAS2L3. Although GAS2 is defined as a family of growth arrest–specific proteins, the significant differences in the expression patterns, interaction characteristics and biological issues or diseases among the different GAS2 family members have not been systemically reviewed to date. Therefore, we summarized the available evidence on the structures and functions of GAS2 family members. This review facilitates a comprehensive molecular understanding of the involvement of the GAS2 family members in an array of biological processes, including cytoskeleton reorganization, cell cycle, apoptosis and cancer development.

GAS2 Promotes Cell Proliferation and Invasion and Suppresses Apoptosis in Pediatric T-Cell Acute Lymphoblastic Leukemia and Activates Wnt/β-Catenin Pathway

Purpose

This study aimed to investigate the effect of growth arrest specific 2 (GAS2) on T-cell acute lymphoblastic leukemia (T-ALL) and its potential molecular mechanism.

Methods

The GAS2 expression level was detected by qRT-RCR and Western blot in normal T lymphocytes and T-ALL cells Jurkat and CCRF-CEM. The proliferation and invasion of Jurkat and CCRF-CEM cells were detected by MTT and Transwell assay, respectively. Apoptosis and cell cycle were measured by flow cytometry. In addition, the chemotherapeutic sensitivity of Jurkat and CCRF-CEM cells was measured MTT assay and flow cytometry.

Results

GAS2 was highly expressed in Jurkat and CCRF-CEM cells. GAS2 could promote cell proliferation and invasion, and inhibit apoptosis of Jurkat and CCRF-CEM cells. GAS2 also promoted cell cycle changes from G0/G1 phase to S phase in Jurkat and CCRF-CEM cells. In addition, GAS2 could reduce the chemotherapeutic sensitivity of Jurkat and CCRF-CEM cells. GAS2 overexpression could promote the expression levels of ki67, proliferating cell nuclear antigen (PCNA), Bcl-2, c-myc, cyclin D1 and β-catenin, while GAS2 knockdown could inhibit their expression levels. Meanwhile, GAS2 overexpression could inhibit Bax expression. Moreover, Wnt/β-catenin pathway inhibitor XAV939 could inhibit the expressions of c-myc, cyclin D1 and β-catenin, but activator LiCl could promote their expression.

Conclusion

Our study demonstrated that GAS2 could promote cell proliferation and invasion, and induce cell cycle, as well as inhibit apoptosis and could activate the Wnt/β-catenin pathway in T-ALL cells.

Dioscin induces prostate cancer cell apoptosis through activation of estrogen receptor-β

Recent researches have shown that estrogen receptor-β (ERβ) activator may be a potent anticancer agent for prostate cancer (PCa), and our previous study also indicated that dioscin can upregulate the expression of ERβ in MC3T3-E1 cell. In the present work, the activity and mechanism of dioscin, a natural product, against PCa were investigated. The results showed that dioscin markedly inhibited cell viability, colony formation, motility and induced apoptosis in PC3 cells. Moreover, dioscin disrupted the formation of PC3 cell-derived mammospheres and reduced aldehyde dehydrogenase (ALDH) level and the CD133+/CD44+ cells, indicating that dioscin had a potent inhibitory activity on prostate cancer stem cells (PCSCs). In vivo results also showed that dioscin significantly suppressed the tumor growth of PC3 cell xenografts in nude mice. Furthermore, mechanism investigation showed that dioscin markedly upregulated ERβ expression level, subsequently increased prolyl hydroxylase 2 level, decreased the levels of hypoxia-inducible factor-1α, vascular endothelial growth factor A and BMI-1, and thus induced cell apoptosis by regulating the expression levels of caspase-3 and Bcl-2 family proteins. In addition, transfection experiment of ERβ-siRNA further indicated that diosicn showed excellent activity against PCa in vitro and in vivo by increasing ERβ expression level. The co-immunoprecipitation (Co-IP) results further suggested that dioscin promoted the interaction of c-ABL and ERβ, but did not change c-ABL expression. Moreover, the molecular docking assay showed that dioscin processed powerful affinity toward to ERβ mainly through the strong hydrogen bonding and hydrophobic effects, and the actions of dioscin on ERβ activation and tumor cells inhibition were significantly weakened in the mutational (Phe-336, Phe-468) PC3 cells. Collectively, these findings proved that dioscin exerted efficient anti-PCa activity via activation of ERβ, which should be developed as an efficient candidate in clinical for treating this cancer in the future.