Claudin1 decrease induced by 1,25-dihydroxy-vitamin D3 potentiates gefitinib resistance therapy through inhibiting AKT activation-mediated cancer stem-like properties in NSCLC cells

ICAT mediates the inhibition of stemness and tumorigenesis in acute myeloid leukemia cells induced by 1,25-(OH)2D3

Background

The role of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) in cancer prevention and treatment is an emerging topic of interest. However, its effects on the stemness of acute myeloid leukemia (AML) cells are poorly understood.

Methods

The proliferation and differentiation of AML cells (HL60 and NB4) were investigated by the CCK-8 assay, immunocytochemical staining, and flow cytometry. The abilities of HL60 and NB4 cells to form spheres were examined by the cell sphere formation assay. In addition, the levels of stemness-associated markers (SOX2, Nanog, OCT4, and c-Myc) in HL60 and NB4 cells were measured by western blotting and quantitative real-time polymerase chain reaction. Moreover, we obtained β-catenin-interacting protein 1 (ICAT)-knockout and ICAT-overexpressing HL-60 cells using gene editing and lentiviral infection techniques and investigated the role of ICAT in modulating the stemness-inhibiting effects of 1,25-(OH)2D3 using the aforementioned experimental methods. Finally, we validated our findings in vivo using NOD/SCID mice.

Results

1,25-(OH)2D3 inhibited the proliferation and stemness of AML cells (HL60 and NB4) and induced their differentiation into monocytes. Additionally, the knockdown of ICAT in HL60 cells attenuated the inhibitory effects of 1,25-(OH)2D3 on proliferation and stemness and suppressed the expression of stemness markers. Conversely, overexpression of ICAT enhanced the aforementioned inhibitory effects of 1,25-(OH)2D3. Consistently, in NOD/SCID mice, 1,25-(OH)2D3 suppressed tumor formation by HL-60 cells, and the effects of ICAT knockdown or overexpression on 1,25-(OH)2D3 aligned with the in vitro findings.

Conclusion

1,25-(OH)2D3 inhibits AML cell stemness, possibly through modulation of the ICAT-mediated Wnt/β-catenin signaling pathway.

CCDC34 maintains stemness phenotype through β-catenin-mediated autophagy and promotes EGFR-TKI resistance in lung adenocarcinoma

Despite recent advances in treatment strategy, lung cancer remains the leading cause of cancer-related mortality worldwide, and it is a serious threat to human health. Lung adenocarcinoma (LUAD) is the most common histological type of lung cancer, and approximately 40-50% of patients with LUAD in Asian populations have epidermal growth factor receptor (EGFR) mutations. The use of EGFR tyrosine kinase inhibitors (EGFR-TKIs) has revolutionarily improved the prognosis of patients with EGFR-mutated LUAD. However, acquired drug resistance is the main cause of treatment failure. Therefore, new therapeutic strategies are necessary to address the resistance to EGFR-TKIs in patients with LUAD. Cancer stemness-related factors lead to multiple-drug resistance in cancer treatment, including EGFR-TKI resistance. Coiled-coil domain-containing 34 (CCDC34) serves as an oncogene in several types of cancer. However, the role and molecular mechanism of CCDC34 in the malignant progression of LUAD have not been reported to date. In the present study, we found that CCDC34 may be associated with LUAD stemness through weighted gene co-expression network analysis (WGCNA). Furthermore, we demonstrated that CCDC34 promoted LUAD stemness properties through β-catenin-mediated regulation of ATG5-induced autophagy, which was conducive to acquired EGFR-TKI resistance in LUAD in vitro and in vivo. Knockdown CCDC34 can synergistically inhibit tumor growth when combined with EGFR-TKIs. This study reveals a positive association between CCDC34 and the stemness phenotype of LUAD, providing new insights into overcoming EGFR-TKI resistance in LUAD by inhibiting CCDC34 expression.

USP40 promotes hepatocellular carcinoma cell proliferation, migration and stemness by deubiquitinating and stabilizing Claudin1

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor that poses a major threat to people's lives and health. Previous studies have found that multiple deubiquitinating enzymes are involved in the pathogenesis of HCC. The purpose of this work was to elucidate the function and mechanism of the deubiquitinating enzyme USP40 in HCC progression.

METHODS

The expression of USP40 in human HCC tissues and HCC cell lines was investigated using RT-qPCR, western blotting and immunohistochemistry (IHC). Both in vitro and in vivo experiments were conducted to determine the crucial role of USP40 in HCC progression. The interaction between USP40 and Claudin1 was identified by immunofluorescence, co-immunoprecipitation and ubiquitination assays.

RESULTS

We discovered that USP40 is elevated in HCC tissues and predicts poor prognosis in HCC patients. USP40 knockdown inhibits HCC cell proliferation, migration and stemness, whereas USP40 overexpression shows the opposite impact. Furthermore, we confirmed that Claudin1 is a downstream gene of USP40. Mechanistically, USP40 interacts with Claudin1 and inhibits its polyubiquitination to stabilize Claudin1 protein.

CONCLUSIONS

Our study reveals that USP40 enhances HCC malignant development by deubiquitinating and stabilizing Claudin1, suggesting that targeting USP40 may be a novel approach for HCC therapy.

Effect of an organic acid blend as an antibiotic alternative on growth performance, antioxidant capacity, intestinal barrier function, and fecal microbiota in weaned piglets

This study was conducted to evaluate the effects of dietary organic acid blend on growth performance, antioxidant capacity, intestinal barrier function, and fecal microbiota in weaned piglets compared with antibiotic growth promoters (AGPs). A total of 90 weaned crossbred barrows (24 ± 1 d of age) with an initial body weight of 7.40 kg were allocated into three experimental treatments. Each treatment consisted of six replicate pens, with five piglets housed in each pen. The dietary treatments included the basal diet (NC), the basal diet supplemented with antibiotics (PC), and the basal diet supplemented with organic acid blend (OA). On day 42, one piglet per pen was randomly selected for plasma and small intestinal sample collection. The results showed that dietary AGP significantly improved growth performance and reduced diarrhea incidence compared to the NC group (P < 0.05). Dietary OA tended to increase body weight on day 42 (P = 0.07) and average daily gain from days 0 to 42 (P = 0.06) and reduce diarrhea incidence (P = 0.05). Dietary OA significantly increased plasma catalase (CAT) activity and decreased the plasma concentration of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin (IL)-8, and IL-6, which were accompanied by upregulated the relative mRNA abundance of superoxide dismutase 1 (SOD1), glutathione peroxidase 1 (GPX1), and nuclear factor erythroid 2-related factor 2 (NRF2) in comparison to that in the NC group (P < 0.05). Moreover, pigs fed the OA diet significantly increased the ratio of villus height to crypt depth and upregulated the relative expression of zonula occludens-1 (ZO-1) and Claudin1 gene in the jejunum compared to the NC group (P < 0.05). Interestingly, dietary AGP or OA did not affect the fecal microbiota structure or volatile fatty acid content (P > 0.05). In conclusion, our results suggested that dietary OA supplementation could improve growth performance and antioxidant capacity and protect the intestinal barrier of weaned piglets, therefore, it has the potential to be considered as an alternative to AGP in the pig industry.

Heterogeneity of cancer stem cell-related marker expression is associated with three-dimensional structures in malignant pleural effusion produced by lung adenocarcinoma

INTRODUCTION

Cancer stem cells have been described in lung adenocarcinoma-associated malignant pleural effusion. They show clinically important features, including the ability to initiate new tumours and resistance to treatments. However, their correlation with the three-dimensional tumour structures in the effusion is not well understood.

METHODS

Cell blocks produced from lung adenocarcinoma patients' pleural effusion were examined for cancer stem cell-related markers Nanog and CD133 using immunocytochemistry. The three-dimensional cancer cell structures and CD133 expression patterns were visualized with tissue-clearing technology. The expression patterns were correlated with tumour cell structures, genetic variants and clinical outcomes.

RESULTS

Thirty-nine patients were analysed. Moderate-to-strong Nanog expression was detected in 27 cases (69%), while CD133 was expressed by more than 1% of cancer cells in 11 cases (28%). Nanog expression was more homogenous within individual specimens, while CD133 expression was detected in single tumour cells or cells within small clusters instead of larger structures in 8 of the 11 positive cases (73%). Although no statistically significant correlation between the markers and tumour genetic variants or patient survival was observed, we recorded seven cases with follow-up specimens after cancer treatment, and four (57%) showed a change in stem cell-related marker expression corresponding to treatment response.

CONCLUSIONS

Lung adenocarcinoma cells in the pleural effusion show variable expression of cancer stem cell-related markers, some showing a correlation with the size of cell clusters. Their expression level is potentially correlated with cancer treatment effects.

Prognostic Profiling of the EMT-Associated and Immunity-Related LncRNAs in Lung Squamous Cell Carcinomas

Lung squamous cell carcinoma (Lung SCC) is associated with metastatic disease, resulting in poor clinical prognosis and a low survival rate. The aberrant epithelial–mesenchymal transition (EMT) and long non-coding RNA (LncRNA) are critical attributors to tumor metastasis and invasiveness in Lung SCC. The present study divided lncRNAs into two subtypes, C1 and C2 (Cluster 1 and Cluster 2), according to the correlation of EMT activity within the public TCGA and GEO databases. Subsequently, the differential clinical characteristics, mutations, molecular pathways and immune cell deconvolution between C1 and C2 were evaluated. Lastly, we further identified three key lncRNAs (DNM3OS, MAGI2-AS3 and LINC01094) that were associated with EMT and, at the same time, prognostic for the clinical outcomes of Lung SCC patients. Our study may provide a new paradigm of metastasis-associated biomarkers for predicting the prognosis of Lung SCC.

CLDN4 promotes growth of acute myeloid leukemia cells via regulating AKT and ERK1/2 signaling

Acute myeloid leukemia (AML) is the most common acute leukemia affecting adults. The tight junction protein CLDN4 is closely related to the development of various epithelial cell carcinomas. However, whether CLDN4 contributes to AML development remains unclear. For the first time, we found that expression of CLDN4 is aberrantly up-regulated in AML cells. Knockdown of CLDN4 expression resulted in a dramatic decreased cell growth, elevated apoptosis of AML cells. Further, we revealed that knockdown of CLDN4 inhibits mRNA expression of PIK3R3 and MAP2K2, thus suppresses activation of AKT and ERK1/2. More importantly, activating AKT branch by SC79 partially compromised CLDN4 knockdown induced cell viability inhibition. In addition, we found that higher expression of CLDN4 is connected to worse survival and is an independent indicator of shorter disease free survival (DFS) in AML patients. Together, our results indicate that CLDN4 contributes to AML pathogenesis, and suggests that targeting CLDN4 is a promising option for AML treatment.