A novel methylated cation channel TRPM4 inhibited colorectal cancer metastasis through Ca2+/Calpain-mediated proteolysis of FAK and suppression of PI3K/Akt/mTOR signaling pathway

Acetalax (Oxyphenisatin Acetate, NSC 59687) and Bisacodyl Cause Oncosis in Triple-Negative Breast Cancer Cell Lines by Poisoning the Ion Exchange Membrane Protein TRPM4

Triple-negative breast cancer (TNBC) is clinically aggressive and relatively unresponsive to current therapies. Therefore, the development of new anticancer agents is needed to satisfy clinical needs. Oxyphenisatin acetate (Acetalax), which had been used as a laxative, has recently been reported to have anticancer activity in murine models. In this study, we demonstrate that Acetalax and its diphenolic laxative structural analogue bisacodyl (Dulcolax) exhibit potent antiproliferative activity in TNBC cell lines and cause oncosis, a nonapoptotic cell death characterized by cellular and nuclear swelling and cell membrane blebbing, leading to mitochondrial dysfunction, ATP depletion, and enhanced immune and inflammatory responses. Mechanistically, we provide evidence that transient receptor potential melastatin member 4 (TRPM4) is poisoned by Acetalax and bisacodyl in MDA-MB468, BT549, and HS578T TNBC cells. MDA-MB231 and MDA-MB436 TNBC cells without endogenous TRPM4 expression as well as TRPM4-knockout TNBC cells were found to be Acetalax- and bisacodyl-resistant. Conversely, ectopic expression of TRPM4 sensitized MDA-MB231 and MDA-MB436 cells to Acetalax. TRPM4 was also lost in cells with acquired Acetalax resistance. Moreover, TRPM4 is rapidly degraded by the ubiquitin-proteasome system upon acute exposure to Acetalax and bisacodyl. Together, these results demonstrate that TRPM4 is a previously unknown target of Acetalax and bisacodyl and that TRPM4 expression in cancer cells is a predictor of Acetalax and bisacodyl efficacy and could be used for the clinical development of these drugs as anticancer agents.

SIGNIFICANCE

Acetalax and bisacodyl kill cancer cells by causing oncosis following poisoning of the plasma membrane sodium transporter TRPM4 and represent a new therapeutic approach for TNBC.

IL-22 activates the PI3K-AKT pathway to promote colorectal cancer cell proliferation and metastasis

BACKGROUND

Colorectal cancer (CRC) is a prevalent malignancy with high morbidity and mortality rates. Previous studies have demonstrated that interleukin (IL)-22 is involved in CRC progression; however, the exact mechanism remains unclear. This study aimed to investigate the effects of IL-22 on CRC cell proliferation and metastasis.

METHODS

IL-22 levels in the serum and tissues of CRC patients were measured using enzyme-linked immunosorbent assay (ELISA). Cell counting kit-8 (CCK-8) assay was used to detect the viability of CRC (HCT116) cells treated with different IL-22 concentrations. Colony formation, Transwell invasion, and scratch assays were employed to assess the effects of IL-22 on cell proliferation, invasion, and migration. Western blotting was performed to measure the expression levels of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), p-PI3K, p-AKT, E-cadherin, matrix metalloproteinase (MMP)-2, MMP-9, SNAI1, and TWIST1 in HCT116 cells treated with IL-22 or a PI3K inhibitor.

RESULTS

ELISA results showed that the expression of IL-22 was significantly increased in the serum and tissues of CRC patients compared to controls. IL-22 treatment increased cell viability and colony formation in a concentration-dependent manner and enhanced cell invasion and migration. Western blotting analysis revealed that IL-22 stimulation upregulated p-PI3K and p-AKT expression, while total PI3K and AKT levels remained unchanged. Additionally, IL-22 also decreased E-cadherin expression and increased the expression of MMP-2, MMP-9, SNAI1, and TWIST1.

CONCLUSIONS

IL-22 activates the PI3K-AKT pathway and promotes HCT116 cell proliferation and metastasis. Targeting the regulation of the PI3K/AKT pathway may be a potential therapeutic strategy for CRC.

SULF1 regulates malignant progression of colorectal cancer by modulating ARSH via FAK/PI3K/AKT/mTOR signaling

BACKGROUND

Colorectal cancer (CRC) has the third highest incidence and second mortality rate of malignant tumors globally, highlighting the urgency to explore the mechanisms underlying CRC progression for refined treatment of this patient population.

METHODS

R Studio was used for data sorting and analysis. Cell apoptosis and cell cycle detection were performed by flow cytometry. Quantitative real-time PCR (qRT-PCR) was used to explore mRNA expression levels. Western blotting was used to explore protein expression levels. CCK8, EdU, and colony formation assays were performed to explore the proliferation capacity of CRC cells. Transwell invasion and migration assays, along with the wound healing assay, were used to explore the invasive and migratory abilities of CRC cells. Subcutaneous Xenograft Assay was utilized to evaluate the tumorigenic capacity of CRC cells in vivo.

RESULTS

SULF1 was highly expressed in CRC samples and cell lines. The knockdown of SULF1 inhibited the proliferation, invasion, and migration of CRC and increased the rate of cell apoptosis. Meanwhile, we demonstrated that SULF1 could negatively regulate ARSH through the FAK/PI3K/AKT/mTOR pathway.

CONCLUSION

We demonstrated that SULF1 could promote CRC progression by regulating ARSH. The SULF1/ARSH/FAK/PI3K/AKT/mTOR signaling pathway represents a promising target for the treatment of this patient population. Colorectal cancer (CRC) has the third highest incidence and second mortality rate of malignant tumors globally. Sulfatase 1 (SULF1) belongs to the sulfatase family, The function of SULF1 in CRC remains elusive. Our study demonstrated that the knockdown of SULF1 could inhibit the proliferation, invasion, and migration of CRC. Meanwhile, our findings indicated that SULF1 could interact with Arylsulfatase Family Member H (ARSH) to regulate the proliferation, invasion, and migration of CRC via the FAK/PI3K/AKT/mTOR signaling pathway. Taken together, our findings suggest that SULF1 might be a new therapeutic target in CRC.

Roles and inhibitors of FAK in cancer: current advances and future directions

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that exhibits high expression in various tumors and is associated with a poor prognosis. FAK activation promotes tumor growth, invasion, metastasis, and angiogenesis via both kinase-dependent and kinase-independent pathways. Moreover, FAK is crucial for sustaining the tumor microenvironment. The inhibition of FAK impedes tumorigenesis, metastasis, and drug resistance in cancer. Therefore, developing targeted inhibitors against FAK presents a promising therapeutic strategy. To date, numerous FAK inhibitors, including IN10018, defactinib, GSK2256098, conteltinib, and APG-2449, have been developed, which have demonstrated positive anti-tumor effects in preclinical studies and are undergoing clinical trials for several types of tumors. Moreover, many novel FAK inhibitors are currently in preclinical studies to advance targeted therapy for tumors with aberrantly activated FAK. The benefits of FAK degraders, especially in terms of their scaffold function, are increasingly evident, holding promising potential for future clinical exploration and breakthroughs. This review aims to clarify FAK's role in cancer, offering a comprehensive overview of the current status and future prospects of FAK-targeted therapy and combination approaches. The goal is to provide valuable insights for advancing anti-cancer treatment strategies.

SH2D4A inhibits esophageal squamous cell carcinoma progression through FAK/PI3K/AKT signaling pathway

Esophageal squamous cell carcinoma (ESCC), one of the most common malignant tumors, is now afflicting approximately 80% of patients diagnosed with esophageal cancers. The therapeutic effect and prognosis of ESCC remain inadequate due to the unusual early symptoms and rapid malignant progression. SH2 Domain containing 4 A (SH2D4A) is downregulated in malignancies and is closely associated with tumor progression. However, neither the biological functions nor the fundamental mechanisms of SH2D4A on ESCC are known. In this study, it was found that SH2D4A is downregulated in ESCC tissues and cell lines. Incorporating immunohistochemistry and clinicopathological findings, we determined that decreased SH2D4A expression was substantially associated with adverse clinical outcomes. Overexpression of SH2D4A inhibited cell proliferation and migration, whereas suppressing SH2D4A has the opposite effect. SH2D4A mechanistically inhibited cells from proliferating and migrating through the FAK/PI3K/AKT signaling pathway. Furthermore, the results of xenograft tumor growth confirmed the preceding findings. In conclusion, our findings reveal that SH2D4A is a gene which can serve as a cancer suppressor in ESCC and may inhibits the ESCC progression by interfering with the FAK/PI3K/AKT signaling pathway. SH2D4A could act as a target for diagnostic or therapeutic purpose in ESCC.

Pancreatic Neuroendocrine Tumors: Signaling Pathways and Epigenetic Regulation

Pancreatic neuroendocrine tumors (PNETs) are characterized by dysregulated signaling pathways that are crucial for tumor formation and progression. The efficacy of traditional therapies is limited, particularly in the treatment of PNETs at an advanced stage. Epigenetic alterations profoundly impact the activity of signaling pathways in cancer development, offering potential opportunities for drug development. There is currently a lack of extensive research on epigenetic regulation in PNETs. To fill this gap, we first summarize major signaling events that are involved in PNET development. Then, we discuss the epigenetic regulation of these signaling pathways in the context of both PNETs and commonly occurring-and therefore more extensively studied-malignancies. Finally, we will offer a perspective on the future research direction of the PNET epigenome and its potential applications in patient care.

A disintegrin and metalloproteinase 22 activates integrin β1 through its disintegrin domain to promote the progression of pituitary adenoma

BACKGROUND

Approximately 35% of pituitary adenoma (PA) display an aggressive profile, resulting in low surgical total resection rates, high recurrence rates, and worse prognosis. However, the molecular mechanism of PA invasion remains poorly understood. Although "a disintegrin and metalloproteinases" (ADAMs) are associated with the progression of many tumors, there are no reports on ADAM22 in PA.

METHODS

PA transcriptomics databases and clinical specimens were used to analyze the expression of ADAM22. PA cell lines overexpressing wild-type ADAM22, the point mutation ADAM22, the mutated ADAM22 without disintegrin domain, and knocking down ADAM22 were generated. Cell proliferation/invasion assays, flow cytometry, immunohistochemistry, immunofluorescence, co-immunoprecipitation, mass spectrometry, Reverse transcription-quantitative real-time PCR, phos-tag SDS-PAGE, and Western blot were performed for function and mechanism research. Nude mice xenograft models and rat prolactinoma orthotopic models were used to validate in vitro findings.

RESULTS

ADAM22 was significantly overexpressed in PA and could promote the proliferation, migration, and invasion of PA cells. ADAM22 interacted with integrin β1 (ITGB1) and activated FAK/PI3K and FAK/ERK signaling pathways through its disintegrin domain to promote PA progression. ADAM22 was phosphorylated by PKA and recruited 14-3-3, thereby delaying its degradation. ITGB1-targeted inhibitor (anti-itgb1) exerted antitumor effects and synergistic effects in combination with somatostatin analogs or dopamine agonists in treating PA.

CONCLUSIONS

ADAM22 was upregulated in PA and was able to promote PA proliferation, migration, and invasion by activating ITGB1 signaling. PKA may regulate the degradation of ADAM22 through post-transcriptional modification levels. ITGB1 may be a potential therapeutic target for PA.

Two Transient Receptor Potential Channels at Focal Adhesions

Recently there have been reports that identify two transient receptor potential channels in cell-matrix junctions known as focal adhesions. These are the calcium channel TRP canonical 7 and the calcium-activated monovalent ion channel, TRP melastatin (TRPM) 4. Here, we report on the occurrence of TRPM4 in focal adhesions of fibroblasts. Of three commercial antibodies recognizing this channel, only one yielded focal adhesion staining, while the other two did not. The epitope recognized by the focal adhesion-localizing antibody was mapped to the extreme C-terminus of the TRPM4 protein. The other two antibodies bind to N-terminal regions of the TRPM4 proteins. Deletion of the TRPM4 gene by CRISPR/cas9 techniques confirmed that this channel is a bona fide focal adhesion component, while expression of full-length TRPM4 proteins suggested that processing may occur to yield a form that localizes to focal adhesions. Given the reports that this channel may influence migratory behavior of cells and is linked to cardiovascular disease, TRPM4 functions in adhesion should be explored in greater depth. (J Histochem Cytochem 71: 495-508, 2023).

Proteomics-based identification of proteins in tumor-derived exosomes as candidate biomarkers for colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer-related death, with high morbidity worldwide. There is an urgent need to find reliable diagnostic biomarkers of CRC and explore the underlying molecular mechanisms. Exosomes are involved in intercellular communication and participate in multiple pathological processes, serving as an important part of the tumor microenvironment.

AIM

To investigate the proteomic characteristics of CRC tumor-derived exosomes and to identify candidate exosomal protein markers for CRC.

METHODS

In this study, 10 patients over 50 years old who were diagnosed with moderately differentiated adenocarcinoma were recruited. We paired CRC tissues and adjacent normal intestinal tissues (> 5 cm) to form the experimental and control groups. Purified exosomes were extracted separately from each tissue sample. Data-independent acquisition mass spectrometry was implemented in 8 matched samples of exosomes to explore the proteomic expression profiles, and differentially expressed proteins (DEPs) were screened by bioinformatics analysis. Promising exosomal proteins were verified using parallel reaction monitoring (PRM) analysis in 10 matched exosome samples.

RESULTS

A total of 1393 proteins were identified in the CRC tissue group, 1304 proteins were identified in the adjacent tissue group, and 283 proteins were significantly differentially expressed between them. Enrichment analysis revealed that DEPs were involved in multiple biological processes related to cytoskeleton construction, cell movement and migration, immune response, tumor growth and telomere metabolism, as well as ECM-receptor interaction, focal adhesion and mTOR signaling pathways. Six differentially expressed exosomal proteins (NHP2, OLFM4, TOP1, SAMP, TAGL and TRIM28) were validated by PRM analysis and evaluated by receiver operating characteristic curve (ROC) analysis. The area under the ROC curve was 0.93, 0.96, 0.97, 0.78, 0.75, and 0.88 (P < 0.05) for NHP2, OLFM4, TOP1, SAMP, TAGL, and TRIM28, respectively, indicating their good ability to distinguish CRC tissues from adjacent intestinal tissues.

CONCLUSION

In our study, comprehensive proteomic profiles were obtained for CRC tissue exosomes. Six exosomal proteins, NHP2, OLFM4, TOP1, SAMP, TAGL and TRIM28, may be promising diagnostic markers and effective therapeutic targets for CRC, but further experimental investigation is needed.

Up-regulation of PUM1 by miR-218-5p promotes colorectal tumor-initiating cell properties and tumorigenesis by regulating the PI3K/AKT axis

Background

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer-related death worldwide. Advanced stage CRC, during the recent past, had a dismal prognosis and only a few available treatments. Pumilio homologous protein 1 (PUM1) is reportedly aberrant in human malignancies, including CRC. However, the role of PUM1 in the regulation of tumor-initiating cells (T-ICs) remains unknown.

Methods

The levels of messenger RNAs (mRNAs) were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunoblot analyses. Statistical analyses were performed to determine the associations between the levels of PUM1 and tumor features and patient outcomes. Whether PUM1 is a downstream target of miR-218-5p was verified by bioinformatics target gene prediction and qRT-PCR.

Results

Herein, it was found that T-ICs, chemoresistance, and recurrent CRC samples all manifest increased PUM1 expression. Functional investigations have shown that PUM1 increased the self-renewal, tumorigenicity, malignant proliferation, and chemoresistance of colorectal cells. PUM1 activates the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway biochemically. Furthermore, it was discovered that miR-218-5p specifically targets T-ICs' PUM1 3'-untranslated region (3'-UTR). More importantly, the PUM1/PI3K/AKT axis regulates CRC cells' responses to treatment with cetuximab, and PUM1 overexpression increased cetuximab resistance. More evidence points to the possibility that low PUM1 may predict cetuximab benefits in CRC patients after analysis of the patient cohort, patient-derived tumor organoids, and patient-derived xenografts (PDXs).

Conclusions

Taken together, the result of this work points to the critical function of the miR-218-5p/PUM1/PI3K/AKT regulatory circuit in regulating T-ICs characteristics and thus suggests possible therapeutic targets for CRC.