CAMSAP2 promotes colorectal cancer cell migration and invasion through activation of JNK/c-Jun/MMP-1 signaling pathway

Effects of Extracellular Matrix Changes Induced by a High-Fat Diet on Gallbladder Smooth Muscle Dysfunction

BACKGROUND

Gallstone formation is a common digestive ailment, with unclear mechanisms underlying its development. Dysfunction of the gallbladder smooth muscle (GSM) may play a crucial role, particularly with a high-fat diet (HFD). This study aimed to investigate the effects of an HFD on GSM and assess how it alters contractility through changes in the extracellular matrix (ECM).

METHODS

Guinea pigs and C57BL/6 mice were fed either an HFD or normal diet (ND). Primary cultures of their (guinea pigs) gallbladder smooth muscle cells (GSMCs) were used for in vitro experiments. Histological stains, RNA-sequencing, bioinformatics analysis, three-dimensional tissue culture, real-time polymerase chain reaction (PCR), Western blot, atomic force microscopy, and muscle tension measurements were performed.

RESULTS

Histological evidence indicated structural changes in the gallbladder muscle layer and ECM collagen deposition in the HFD group. The HFD group also showed increased expression of collagen, integrin family, and matrix metalloproteinase (MMP) and the phosphoinositide 3-kinase (PI3K)-protein kinase B (PKB/Akt) signaling pathway. Compared with GSMCs cultured on Matrigel containing 1 mg/mL of collagen I, those cultured with 2 mg/mL showed a phenotype change from contractile to synthetic cells. Consistent with these findings, the HFD group also demonstrated increased ECM stiffness and decreased smooth muscle contractility.

CONCLUSIONS

Our findings reveal a mechanism by which an HFD alters the ECM composition of the gallbladder muscle, activating the integrin/PI3K-Akt/MMP signaling pathway, thereby impacting GSMC phenotype and contractility. These insights enhance the understanding of gallstone formation mechanism and provide potential therapeutic targets to treat gallbladder dysfunction.

IL-4 Downregulates PD-L1 Level Via SOCS1 Upregulation-Induced JNK Deactivation to Enhance Antitumor Immunity in In Vitro Colorectal Cancer

Interleukin-4 (IL-4) controls cell growth and immune system regulation in tumorigenesis and can inhibit the growth of colon cancer cell lines, but the possible mechanism is unclear. In this study, we investigated the possible mechanism of IL-4 in colorectal cancer (CRC) through in vitro experiments. CRC cells received treatment with IL-4 (50 ng/mL), investigating the suppressor of cytokine signaling 1 (SOCS1)-related mechanism underlying the role of IL-4 in the progression and immunosuppression of CRC. The malignant processes of CRC cells and CD8+T cell-mediated immune response in CRC cells were determined by CCK-8, Transwell, wound healing, and flow cytometry assays. Programmed death ligand 1 (PD-L1), SOCS1 expressions, and c-Jun N-terminal kinase (JNK) activation in CRC cells were analyzed by quantitative reverse transcription polymerase chain reaction and/or Western blot. IL-4 repressed the malignant processes, yet promoted the apoptosis of CRC cells. Besides, IL-4 downregulated PD-L1 level, upregulated SOCS1 level, and restrained JNK activation in CRC cells, while enhancing CRC cell-killing effect of CD8+T cells. IL-4-induced effects on the aforementioned malignant processes of CRC cells and the killing effect of CD8+T cells toward CRC cells were all reversed when SOCS1 was knocked down in the CRC cells. IL-4 downregulates PD-L1 level via SOCS1 upregulation-induced JNK deactivation to enhance antitumor immunity in in vitro CRC. The study provides a theoretical basis for the clinical application of IL-4 in antitumor immunity in CRC.

CAMSAP3-mediated regulation of HMGB1 acetylation and subcellular localization in lung cancer cells: Implications for cell death modulation

BACKGROUND

Deregulation of cell death is a common characteristic of cancer, and resistance to this process often occurs in lung cancer. Understanding the molecular mechanisms underlying an aberrant cell death is important. Recent studies have emphasized the involvement of calmodulin-regulated spectrin-associated protein 3 (CAMSAP3) in lung cancer aggressiveness, its influence on cell death regulation remains largely unexplored.

METHODS

CAMSAP3 was knockout in lung cancer cells using CRISPR-Cas9 system. Cell death and autophagy were evaluated using MTT and autophagic detection assays. Protein interactions were performed by proteomic analysis and immunoprecipitation. Protein expressions and their cytoplasmic localization were analyzed through immunoblotting and immunofluorescence techniques.

RESULTS

This study reveals a significant correlation between low CAMSAP3 expression and poor overall survival rates in lung cancer patients. Proteomic analysis identified high mobility group box 1 (HMGB1) as a candidate interacting protein involved in the regulation of cell death. Treatment with trichostatin A (TSA), an inhibitor of histone deacetylases (HDACs) resulted in increased HMGB1 acetylation and its translocation to the cytoplasm and secretion, thereby inducing autophagic cell death. However, this process was diminished in CAMSAP3 knockout lung cancer cells. Mechanistically, immunoprecipitation indicated an interaction between CAMSAP3 and HMGB1, particularly with its acetylated form, in which this complex was elevated in the presence of TSA.

CONCLUSIONS

CAMSAP3 is prerequisite for TSA-mediated autophagic cell death by interacting with cytoplasmic acetylated HMGB1 and enhancing its release.

SIGNIFICANT

This finding provides molecular insights into the role of CAMSAP3 in regulating cell death, highlighting its potential as a therapeutic target for lung cancer treatment.

The epithelial adherens junction component PLEKHA7 regulates ECM remodeling and cell behavior through miRNA-mediated regulation of MMP1 and LOX

Epithelial adherens junctions (AJs) are cell-cell adhesion complexes that are influenced by tissue mechanics, such as those emanating from the extracellular matrix (ECM). Here, we introduce a mechanism whereby epithelial AJs can also regulate the ECM. We show that the AJ component PLEKHA7 regulates levels and activity of the key ECM remodeling components MMP1 and LOX in well-differentiated colon epithelial cells, through the miR-24 and miR-30c miRNAs. PLEKHA7 depletion in epithelial cells results in LOX-dependent ECM remodeling in culture and in the colonic mucosal lamina propria in mice. Furthermore, PLEKHA7-depleted cells exhibit increased migration and invasion rates that are MMP1- and LOX- dependent, and form colonies in 3D cultures that are larger in size and acquire aberrant morphologies in stiffer matrices. These results reveal an AJ-mediated mechanism, through which epithelial cells drive ECM remodeling to modulate their behavior, including acquisition of phenotypes that are hallmarks of conditions such as fibrosis and tumorigenesis.

Potential Mechanism of Tibetan Medicine Liuwei Muxiang Pills against Colorectal Cancer: Network Pharmacology and Bioinformatics Analyses

This study aimed to explore the mechanism through which Tibetan medicine Liuwei Muxiang (LWMX) pills acts against colorectal cancer (CRC). We firstly retrieved the active ingredients and the correlated targets of LWMX pills from public databases. The CRC-related targets were determined through bioinformatic analysis of a public CRC dataset. By computing the intersection of the drug-specific and disease-related targets, LWMX pill-CRC interaction networks were constructed using the protein-protein interaction (PPI) method and functional enrichment analysis. Subsequently, we determined the hub genes using machine learning tools and further verified their critical roles in CRC treatment via immune infiltration analysis and molecular docking studies. We identified 81 active ingredients in LWMX pills with 614 correlated targets, 1877 differentially expressed genes, and 9534 coexpression module genes related to CRC. A total of 5 target hub genes were identified among the 108 intersecting genes using machine learning algorithms. The immune infiltration analysis results suggested that LWMX pills could affect the CRC immune infiltration microenvironment by regulating the expression of the target hub genes. Finally, the molecular docking outcomes revealed stable binding affinity between all target hub proteins and the primary active ingredients of LWMX pills. Our findings illustrate the anti-CRC potential and the mechanism of action of LWMX pills and provide novel insights into multitarget medication for CRC treatment.

CAMSAP2 enhances lung cancer cell metastasis by mediating RASAL2 degradation

AIMS

Cancer metastasis significantly contributes to mortality in lung cancer patients. Calmodulin-regulated spectrin-associated protein family member 2 (CAMSAP2) plays a significant role in cancer cell migration; however, its role in lung cancer metastasis and the underlying mechanism remain largely unknown. The present study aimed to investigate the impact of CAMSAP2 on lung cancer.

MAIN METHODS

The clinical relevance of CAMSAP2 in lung cancer patients was assessed using public database. RNA interference experiments were conducted to investigate role of CAMSAP2 in cell migration through transwell and wound healing assays. Molecular mechanisms were explored by identifying the possible interacting partners and pathways using the BioGRID and KEGG pathway analyses. The impact of CAMSAP2 on Ras protein activator-like 2 (RASAL2)-mediated lung cancer metastasis was investigated through biochemical assays. Additionally, in vivo experimentation using a murine tail vein metastasis model was performed to comprehend CAMSAP2's influence on metastasis.

KEY FINDINGS

A high expression level of CAMSAP2 was associated with poor overall survival in lung cancer patients and it positively correlated with cell migration in non-small cell lung cancer (NSCLC) cell lines. Knockdown of CAMSAP2 inhibited lung cancer cell motility in vitro and metastasis in vivo. Proteomic and biochemical analyses revealed the interaction between CAMSAP2 and RASAL2, which facilitates the degradation of RASAL2 through the ubiquitin-proteasome system. These degradation processes resulted in the activation of the extracellular signal-regulated kinase (ERK) signaling pathway, thereby promoting lung cancer metastasis. Collectively, the results of this study suggest that CAMSAP2 is a crucial regulator of cancer cell migration and metastasis and a promising therapeutic target for lung cancer.

[High expression of CAMSAP2 promotes invasion and metastasis of gastric cancer cells by upregulating TGF-β signaling]

OBJECTIVE

To investigate the expression of calmodulin-regulated spectrin-associated protein 2 (CAMSAP2) in gastric cancer and its effect on gastric cancer cell invasion and metastasis.

METHODS

The association of CAMSAP2 expression levels with progression and prognosis of gastric cancer was analyzed using public cancer data and in 106 patients receiving radical gastrectomy in our hospital from October, 2013 to October, 2017. The biological functions of CAMSAP2 were predicted using bioinformatics analysis. Gastric cancer MGC803 cells with CAMSAP2 overexpression and knockdown were observed for epithelial-mesenchymal transition (EMT), migration and invasion. A nude mouse model bearing orthotopic gastric cancer cell xenografts was established for verifying the results and exploring the underlying molecular mechanism.

RESULTS

Gastric cancer tissues expressed high levels of CAMSAP2, which were positively correlated with CEA and CA19-9 (P<0.001). Cox regression analysis showed that CAMSAP2 expression level was an independent risk factor affecting the 5-year survival rate of gastric cancer patients (HR=2.969, 95% CI: 1.031-8.548). Enrichment analysis suggested that CAMSAP2 was involved in epithelialmesenchymal transition (EMT) and TGF-β signaling. In gastric cancer cells, CAMSAP2 overexpression significantly increased the expressions of vimentin and N-cadherin, inhibited the expression of E-cadherin, and enhanced cell migration and invasion (P<0.05); CAMSAP2 knockdown produced the opposite effects in the cells (P<0.05). In the tumor- bearing mice, xenografts overexpressing CAMSAP2 showed enhanced metastasis (P<0.05), increased vimentin and N-cadherin expressions and lowered E-cadherin expression (P<0.05), and the xenografts with CAMSAP2 knockdown showed the opposite changes (P<0.05). Both the in vivo and in vitro experiments showed that CAMSAP2 overexpression increased and CAMSAP2 knockdown lowered the levels of TGF-β and p-Smad2/3 in the gastric cancer cells (P<0.05).

CONCLUSION

The high expression of CAMSAP2 contributes to disease progression and poor prognosis of gastric cancer possibly by upregulating TGF-β signaling to promote EMT.

A hybrid deep forest-based method for predicting synergistic drug combinations

Combination therapy is a promising approach in treating multiple complex diseases. However, the large search space of available drug combinations exacerbates challenge for experimental screening. To predict synergistic drug combinations in different cancer cell lines, we propose an improved deep forest-based method, ForSyn, and design two forest types embedded in ForSyn. ForSyn handles imbalanced and high-dimensional data in medium-/small-scale datasets, which are inherent characteristics of drug combination datasets. Compared with 12 state-of-the-art methods, ForSyn ranks first on four metrics for eight datasets with different feature combinations. We conduct a systematic analysis to identify the most appropriate configuration parameters. We validate the predictive value of ForSyn with cell-based experiments on several previously unexplored drug combinations. Finally, a systematic analysis of feature importance is performed on the top contributing features extracted by ForSyn. The resulting key genes may play key roles on corresponding cancers.

Effects of Epigallocatechin-3-Gallate on Matrix Metalloproteinases in Terms of Its Anticancer Activity

Epidemiological studies have shown that the consumption of green tea has beneficial effects against cancer. Basic studies have provided evidence that epigallocatechin gallate (EGCG) is a major contributor to these effects. Matrix metalloproteinases (MMPs) are zinc-dependent metalloproteinases with the ability to degrade the extracellular matrix proteins and are involved in various diseases including cancer in which MMPs have a critical role in invasion and metastasis. In this review, we discuss the effects of EGCG on several types of MMPs in the context of its anticancer activity. In the promoter region, MMPs have binding sites for at least one transcription factor of AP-1, Sp1, and NF-κB, and EGCG can downregulate these transcription factors through signaling pathways mediated by reactive oxygen species. EGCG can also decrease nuclear ERK, p38, heat shock protein-27 (Hsp27), and β-catenin levels, leading to suppression of MMPs' expression. Other mechanisms by which EGCG inhibits MMPs include direct binding to MMPs to prevent their activation and downregulation of NF-κB to suppress the production of inflammatory cytokines such as TNFα and IL-1β. Findings from studies on EGCG presented here may be useful in the development of more effective anti-MMP agents, which would give beneficial effects on cancer and other diseases.