Downregulation of PTPN18 can inhibit proliferation and metastasis and promote apoptosis of endometrial cancer

HEATR3 involved in the cell proliferation, metastasis and cell cycle development of bladder cancer acts as a tumor suppressor

The study was designed to detect the expression and clinical significance of the HEATR3 gene in bladder cancer (BCa) and to preliminarily explore whether this gene can affect the occurrence and development of BCa through the AKT/ERK signaling pathway. The expression and prognostic value of HEATR3 were explored based on The Cancer Genome Atlas (TCGA) and Genotypic Tissue Expression (GTEx) databases. Microarray immunohistochemical analysis was performed in 30 BCa cases to investigate the level of HEATR3 protein and to explore the relationship between HEATR3 and the clinicopathological features of BCa. Western Blot and qRT-PCR were used to detect HEATR3 protein and mRNA in BCa cell lines (5637, TCCSUP, SW780) and fallopian tube epithelial cell (SV-HUC-1). CCK8 method was employed to study the proliferation of BCa cells after heat treatment. Transwell assay was conducted to analyze the effect of HEATR3 on cell migration and invasion. And cell cycle and apoptosis were detected by flow cytometry. Furthermore, Western Blot assay was used to probe the effects of down-regulation of HEATR3 expression on the expression and phosphorylation levels of AKT and ERK proteins in BCa cells. Bioinformatics analysis showed that HEATR3 was significantly up-regulated in BCa, and high HEATR3 expression was associated with poor prognosis of BCa patients. In vitro experiments demonstrated that HEATR3 expression was up-regulated in BCa tissues compared with that in adjacent tissues. HEATR3 protein was also up-regulated in malignant cell lines. HEATR3 knockdown in BCa cells could inhibit cell proliferation, invasion and migration, block cell cycle and promote cell apoptosis. At the same time, HEATR3 knockdowns reduced the expression levels of p-AKT and p-ERK proteins. HEATR3 knockdown inhibits the development of BCa cells through the AKT/ERK signaling pathway. and it may become one of the most promising molecular targets for BCa treatment.

Natural products modulate cell apoptosis: a promising way for treating endometrial cancer

Endometrial cancer (EC) is a prevalent epithelial malignancy in the uterine corpus's endometrium and myometrium. Regulating apoptosis of endometrial cancer cells has been a promising approach for treating EC. Recent in-vitro and in-vivo studies show that numerous extracts and monomers from natural products have pro-apoptotic properties in EC. Therefore, we have reviewed the current studies regarding natural products in modulating the apoptosis of EC cells and summarized their potential mechanisms. The potential signaling pathways include the mitochondria-dependent apoptotic pathway, endoplasmic reticulum stress (ERS) mediated apoptotic pathway, the mitogen-activated protein kinase (MAPK) mediated apoptotic pathway, NF-κB-mediated apoptotic pathway, PI3K/AKT/mTOR mediated apoptotic pathway, the p21-mediated apoptotic pathway, and other reported pathways. This review focuses on the importance of natural products in treating EC and provides a foundation for developing natural products-based anti-EC agents.

PTPN18 Serves as a Potential Oncogene for Glioblastoma by Enhancing Immune Suppression

Glioblastoma is characterized as one of the deadliest cancers in humans. The survival time is not improved by standard treatment. Although immunotherapy has revolutionized cancer treatment, the current therapy targets for glioblastoma patients are not satisfied. We systematically analyzed the expression patterns, predictive values, and immunological characteristics of PTPN18 in glioblastoma. The independent datasets and functional experiments were employed to validate our findings. Our data showed that PTPN18 is potentially cancerogenic in glioblastoma with advanced grades and poor prognosis. High expression of PTPN18 correlated with CD8⁺ T cell exhaustion and immune suppression in glioblastoma. In addition, PTPN18 facilitates glioblastoma progression by accelerating glioma cell prefiltration, colony formation, and tumor growth in mice. PTPN18 also promotes cell cycle progression and inhibits apoptosis. Our results illustrate the characterization of PTPN18 in glioblastoma and highlight the potential value as an immunotherapeutic target for glioblastoma treatment.

Comprehensive analysis of PTPN gene family revealing PTPN7 as a novel biomarker for immuno-hot tumors in breast cancer

Background: The non-receptor protein tyrosine phosphatase (PTPN) gene family has been considered to be involved in the oncogenesis and development of multiple cancers. However, its prognostic utility and immunological relevance in breast cancer (BrCa) have not been clarified.

Methods: A transcriptional level interpretation of the expressions and prognostic values was analyzed using the data from The Cancer Genome Atlas (TCGA) cohort. In addition, GO and DAVID pinpoint the functional enrichment of PTPNs. Moreover, the immune correlations of PTPN7 in BrCa and pan-cancer were further investigated based on the TCGA cohort and were testified using the in-house and the Gene Expression Omnibus (GEO) cohorts.

Results: For systematic analysis of the PTPN family, we found that the expression levels of PTPN1, PTPN6, PTPN7, PTPN18, PTPN20, and PTPN22 was promoted in tumor tissues while comparing with paraneoplastic tissues during our study. We further investigated their functions and protein-protein interactions (PPI), and these results strongly suggested that PTPN family was associated with protein dephosphorylation. Next, we performed an immunological relevance analysis and found that PTPN7 was correlated with immune infiltration, suggesting a stronger association of PTPN7 with immuno-hot tumors in BrCa. In addition, results from the in-house cohort confirmed the positive correlation between PTPN7 and PD-L1. The pan-cancer analysis revealed that PTPN7 was related to PD-L1 and CTLA-4 expression in almost all cancer types. Finally, the predictive value of PTPN7 for immunotherapy was significant in two independent GEO cohorts.

Conclusion: In conclusion, this is the first extensive research on the correlation between PTPN family expression and immune characterization in BrCa. As results, PTPN7 expression is associated with immuno-hot tumors and could be a promising predictive biomarker for immunotherapy in not only BrCa but multiple cancers.

Nuclear import of PTPN18 inhibits breast cancer metastasis mediated by MVP and importin β2

Distant metastasis is the primary cause of breast cancer-associated death. The existing information, such as the precise molecular mechanisms and effective therapeutic strategies targeting metastasis, is insufficient to combat breast cancer. This study demonstrates that the protein tyrosine phosphatase PTPN18 is downregulated in metastatic breast cancer tissues and is associated with better metastasis-free survival. Ectopic expression of PTPN18 inhibits breast cancer cell metastasis. PTPN18 is translocated from the cytoplasm to the nucleus by MVP and importin β2 in breast cancer. Then, nuclear PTPN18 dephosphorylates ETS1 and promotes its degradation. Moreover, nuclear PTPN18 but not cytoplasmic PTPN18 suppresses transforming growth factor-β signaling and epithelial-to-mesenchymal transition by targeting ETS1. Our data highlight PTPN18 as a suppressor of breast cancer metastasis and provide an effective antimetastatic therapeutic strategy.

Critical roles of PTPN family members regulated by non-coding RNAs in tumorigenesis and immunotherapy

Since tyrosine phosphorylation is reversible and dynamic in vivo, the phosphorylation state of proteins is controlled by the opposing roles of protein tyrosine kinases (PTKs) and protein tyrosine phosphatase (PTPs), both of which perform critical roles in signal transduction. Of these, intracellular non-receptor PTPs (PTPNs), which belong to the largest class I cysteine PTP family, are essential for the regulation of a variety of biological processes, including but not limited to hematopoiesis, inflammatory response, immune system, and glucose homeostasis. Additionally, a substantial amount of PTPNs have been identified to hold crucial roles in tumorigenesis, progression, metastasis, and drug resistance, and inhibitors of PTPNs have promising applications due to striking efficacy in antitumor therapy. Hence, the aim of this review is to summarize the role played by PTPNs, including PTPN1/PTP1B, PTPN2/TC-PTP, PTPN3/PTP-H1, PTPN4/PTPMEG, PTPN6/SHP-1, PTPN9/PTPMEG2, PTPN11/SHP-2, PTPN12/PTP-PEST, PTPN13/PTPL1, PTPN14/PEZ, PTPN18/PTP-HSCF, PTPN22/LYP, and PTPN23/HD-PTP, in human cancer and immunotherapy and to comprehensively describe the molecular pathways in which they are implicated. Given the specific roles of PTPNs, identifying potential regulators of PTPNs is significant for understanding the mechanisms of antitumor therapy. Consequently, this work also provides a review on the role of non-coding RNAs (ncRNAs) in regulating PTPNs in tumorigenesis and progression, which may help us to find effective therapeutic agents for tumor therapy.

PTPN18 Stimulates the Development of Ovarian Cancer by Activating the PI3K/AKT Signaling

Objective

To illustrate the functions of protein tyrosine phosphatase nonreceptor type 18 (PTPN18) in the progression of ovarian cancer and the potential molecular mechanism.

Methods

Differential PTPN18 expression in ovarian cancer samples was determined. Following PTPN18 knockdown, changes in proliferation and migration in ovarian cancer cells were detected. Nude mice with ovarian cancer were used to uncover the effects of PTPN18 on ovarian cancer growth in vivo.

Results

PTPN18 was significantly upregulated in ovarian cancer samples and linked to pathological staging and metastasis rate. PTPN18 displayed prognostic and diagnostic potentials in ovarian cancer. Knockdown of PTPN18 and treatment of the PI3K inhibitor could inhibit proliferative and migratory abilities in ovarian cancer cells. Moreover, PTPN18 was capable of inactivating PI3K/AKT signaling. In vivo knockdown of PTPN18 suppressed ovarian cancer growth in nude mice.

Conclusions

PTPN18 is upregulated in ovarian cancer, which stimulates the malignant development by activating PI3K/AKT signaling. The PTPN18 level is also associated with pathological staging and metastasis in ovarian cancer patients, which may be utilized as a hallmark predicting the malignant level.

Roles of ferroptosis in urologic malignancies

Ferroptosis, an iron-dependent form of non-apoptotic cell death, is believed to strongly contribute to the pathogenesis of multiple cancers. Recently, the positive association between ferroptosis and urologic malignancies has drawn considerable attention, while a comprehensive review focused on this issue is absent. Based on this review, ferroptosis has been implicated in the development and therapeutic responses of prostate cancer, kidney cancer, and bladder cancer. Mechanistically, a large number of biomolecules and tumor-associated signaling pathways, including DECR1, PANX2, HSPB1, ACOT8, SUV39H1, NCOA4, PI3K-AKT-mTOR signaling, VHL/HIF-2α pathway, and Hippo/TAZ signaling pathway, have been reported to regulate ferroptosis in urologic cancers. Ferroptosis inducers, such as erastin, ART, CPNPs, and quinazolinyl-arylurea derivatives, exert potential therapeutic effects per se and/or enhance the anticancer response of other anticancer drugs in urologic oncology. A better understanding of ferroptosis may provide a promising way to treat therapy-resistant urologic cancers.

PTPN18 promotes colorectal cancer progression by regulating the c-MYC-CDK4 axis

Protein tyrosine phosphatase non-receptor type 18 (PTPN18) is often highly expressed in colorectal cancer (CRC), but its role in this disease remains unclear. We demonstrated that PTPN18 overexpression promotes growth and tumorigenesis in CRC cells and that PTPN18 deficiency yields the opposite results in vitro. Moreover, a xenograft assay showed that PTPN18 deficiency significantly inhibited tumorigenesis in vivo. PTPN18 activated the MYC signaling pathway and enhanced CDK4 expression, which is tightly associated with the cell cycle and proliferation in cancer cells. Finally, we found that MYC interacted with PTPN18 and increased the protein level of MYC. In conclusion, our results suggest that PTPN18 promotes CRC development by stabilizing the MYC protein level, which in turn activates the MYC-CDK4 axis. Thus, PTPN18 could be a novel therapeutic target in the future.

Protein tyrosine phosphatases in cell adhesion

Adhesive structures between cells and with the surrounding matrix are essential for the development of multicellular organisms. In addition to providing mechanical integrity, they are key signalling centres providing feedback on the extracellular environment to the cell interior, and vice versa. During development, mitosis and repair, cell adhesions must undergo extensive remodelling. Post-translational modifications of proteins within these complexes serve as switches for activity. Tyrosine phosphorylation is an important modification in cell adhesion that is dynamically regulated by the protein tyrosine phosphatases (PTPs) and protein tyrosine kinases. Several PTPs are implicated in the assembly and maintenance of cell adhesions, however, their signalling functions remain poorly defined. The PTPs can act by directly dephosphorylating adhesive complex components or function as scaffolds. In this review, we will focus on human PTPs and discuss their individual roles in major adhesion complexes, as well as Hippo signalling. We have collated PTP interactome and cell adhesome datasets, which reveal extensive connections between PTPs and cell adhesions that are relatively unexplored. Finally, we reflect on the dysregulation of PTPs and cell adhesions in disease.

Silencing of PTPN18 Induced Ferroptosis in Endometrial Cancer Cells Through p-P38-Mediated GPX4/xCT Down-Regulation

Background

Endometrial cancer (EC) is the fourth most common neoplasm and the eighth leading cause of cancer death in females worldwide. PTPN18 is a member of the protein tyrosine phosphatases (PTP) family, which is associated with the occurrence and progression of various human cancers. PTPN18 was up-regulated in endometrial cancer tissues and high level of PTPN18 promoted proliferation and metastasis of EC cells.

Methods

The expression of PTPN18, GPX4 and xCT in endometrial cancer tissues and KLE cells was detected by immunohistochemistry and Western blot, respectively. Lentiviral transfection were used to silence PTPN18 level in KLE cells. The Ros level in KLE cells was examined by ELISA assay.

Results

In the present study, we found that silencing of PTPN18 induced ferroptosis in KLE endometrial cancer cells. PTPN18 knockdown increased intracellular ROS level and down-regulated GPX4 and xCT expression. Besides, silencing of PTPN18 also induced the expression of p-p38.

Conclusion

We concluded that silencing of PTPN18 might induce ferroptosis by targeting the p-p38/GPX4/xCT axis. The results provide critical insight into the application of PTPN18 knockdown in EC intervention.

Cisplatin Changes Expression of SEMA3B in Endometrial Cancer

BACKGROUND

Semaphorin 3B (SEMA3B) is characterized as a strong suppressing factor of the proliferation of cancerous cells and also by its anti-angiogenic effect. However, the knowledge on the changes in the expression profile of SEMA3B under the influence of cisplatin in endometrial cancer remains fragmented. The aim of this work was to note the changes in expression of SEMA3B when under the influence of cisplatin in the endometrial cancer cell line.

METHODS

Ishikawa cell line cells were exposed to three different concentrations of cisplatin: 2.5μM; 5μM; 10μM for 12, 24 and 48 hours and were compared to cells untreated by the drug. Changes in the expression profile of SEMA3B were determined based upon RtqPCR (mRNA) alongside the ELISA assay (protein). The Statistica 13.0 PL program was used for statistical analysis (p<0.05).

RESULTS

Changes on the transcriptome level seem to be more dynamic than on the proteome level. Regardless of the concentration given or the exposition period, the expression of semaphorin 3B was, in fact, higher in cells exposed to cisplatin. Statistically substantial differences (p<0.05) in the expression of SEMA3B mRNA and protein were seen for all incubation periods at the given cisplatin level when compared to the control.

CONCLUSION

Cisplatin causes a growth in the expression of SEMA3B in an endometrial cancer cell culture, this results in the restoration in the state of cell homeostasis and shows the effectiveness of pharmacotherapy, including a low risk of drug resistance.