Cdc42-driven endosomal cholesterol transport promotes collateral resistance in HER2-positive gastric cancer.

Resistance to trastuzumab and the poor efficacy of subsequent chemotherapy have become major challenges for HER2-positive gastric cancer (GC). As resistance evolves, tumor cells may acquire a new drug susceptibility profile, profoundly impacting the subsequent treatment selection and patient survival. However, the interplay between trastuzumab and other types of drugs in HER2-positive GC remains elusive. In our study, we utilized resistant cell lines and tissue specimens to map the drug susceptibility profile of trastuzumab-resistant GC, discovering that resistance to trastuzumab induces collateral resistance to commonly used chemotherapeutic agents. Additionally, patients with collateral resistance distinguished by a 13-gene scoring model in HER2-positive GC cohorts are predicted to have a poor prognosis and may be sensitive to cholesterol-lowering drugs. Mechanistically, endosomal cholesterol transport is further confirmed to enrich cholesterol in the plasma membrane, contributing to collateral resistance through the Hedgehog-ABCB1 axis. As a driver for cholesterol, Cdc42 is activated by the formation of the NPC1-TßRI-Cdc42 complex to facilitate endosomal cholesterol transport. We demonstrated that inhibiting Cdc42 activation with ZCL278 reduces cholesterol levels in the plasma membrane and reverses collateral resistance between trastuzumab and chemotherapy in vitro and in vivo. Collectively, our findings verify the phenomena and mechanism of collateral resistance between trastuzumab and chemotherapy, and propose a potential therapeutic target and strategy in the second-line treatment for trastuzumab-resistant HER2-positive GC.

Aberrant LETM1 elevation dysregulates mitochondrial functions and energy metabolism and promotes lung metastasis in osteosarcoma.

Osteosarcoma is a differentiation-deficient disease, and despite the unique advantages and great potential of differentiation therapy, there are only a few known differentiation inducers, and little research has been done on their targets. Cell differentiation is associated with an increase in mitochondrial content and activity. The metabolism of some tumor cells is characterized by impaired oxidative phosphorylation, as well as up-regulation of aerobic glycolysis and pentose phosphate pathways. Leucine-containing zipper and EF-hand transmembrane protein 1 (LETM1) is involved in the maintenance of mitochondrial morphology and is closely associated with tumorigenesis and progression, as well as cancer cell stemness. We found that MG63 and 143B osteosarcoma cells overexpress LETM1 and exhibit abnormalities in mitochondrial structure and function. Knockdown of LETM1 partially restored the mitochondrial structure and function, inhibited the pentose phosphate pathway, promoted oxidative phosphorylation, and led to osteogenic differentiation. It also inhibited spheroid cell formation, proliferation, migration, and invasion in an in vitro model. When LETM1 was knocked down in vivo, there was reduced tumor formation and lung metastasis. These data suggest that mitochondria are aberrant in LETM1-overexpressing osteosarcoma cells, and knockdown of LETM1 partially restores the mitochondrial structure and function, inhibits the pentose phosphate pathway, promotes oxidative phosphorylation, and increases osteogenic differentiation, thereby reducing malignant biological behavior of the cells.

Resveratrol ameliorates intestinal lipid metabolism through the PPAR signaling pathway in high-fat diet-fed red tilapia (Oreochromis niloticus).

Feeding high-fat (HF) diets has been shown to cause hepatic and intestinal impairment in fish species, but the mode of action, especially the pathways involved in the intestine, has not been determined yet. In this study, the effects of resveratrol (RES) supplementation on the intestinal structure, microbial flora, and fat metabolism in red tilapia (Oreochromis niloticus) were determined. The results showed RES maintained the structural integrity of the intestine and significantly increased the number of goblet cells in the midgut. RES significantly induced interferon (IL)-1ß, IL-6, IL-10, and tumor necrosis factor (TNF)-α, serumal and fecal trimetlylamine oxide (TMAO) and lipopolysaccharides (LPS), intestinal acetic acid levels. However, the concentrations of bound bile acids increased in HF-fed red tilapia. Atp5fa1 and Pafah1b3 significantly increased, Pmt and Acss2 significantly decreased, respectively, with RES supplementation, which was alleviated and retained at the same level in the selisistat (EX527) group. While for transcriptome and proteomics results, RES was found to promote fatty acid ß-oxidation and arachidonic acid metabolism associated with the peroxisome proliferator-activated receptor (PPAR) signaling pathway. The next validation experiment showed some genes related to apoptosis and fatty acid metabolism pathways were altered by RES supplementation. Namely, sn6, loc100702698, new_14481, and prkaa1 were upregulated, while ffrs1, ap3s1, and loc100705861 were downregulated. RES significantly increased Planctomycetes and Verrucomicrobia while decreased Moonvirus, Citrobacter, and Pseudomonas. Akkermansia and Fusobacterium significantly increased and Aeromonas significantly decreased. Thus, unsaturated fatty acid biosynthesis significantly increased and carbohydrate/energy metabolism decreased. To conclude, RES enabled the body to complete fatty acid ß-oxidation and arachidonic acid metabolism, whereas the addition of inhibitors increased the expression of the phagosome transcriptome and reduced fatty acid ß-oxidative metabolism.

Potent salinomycin C20-O-alkyl oxime derivative SAL-98 efficiently inhibits tumor growth and metastasis by affecting Wnt/ß-catenin signal pathway.

The dysregulation of Wnt/ß-catenin signaling pathway is closely related to tumorigenesis, metastasis and cancer stem cell maintenance. Salinomycin is a polyether ionophore antibiotic that selectively eliminates cancer stem cells by inhibiting the Wnt/ß-catenin signal pathway. Salinomycin selectively target cancer stem cells, but the toxicity limits its further use. In this study, we explore the anti-tumor mechanism of one most active salinomycin C20-O-alkyl oximederivative SAL-98 and found that SAL-98 exerts 10 times higher anti-tumor and anti-CSCs activities compared with salinomycin, which induces cell cycle arrest, ER stress and mitochondria dysfunction and inhibits Wnt/ß-catenin signal pathway in vitro with high efficacy. Moreover, SAL-98 shows good anti-metastasis effect in vivo. In addition, SAL-98 demonstrates same anti-tumor activities as salinomycin with less 5 times concentration in vivo, the ER stress, autophagy and anti-CSCs effects were also confirmed in vivo. Mechanistically, SAL-98 inhibits the Wnt/ß-catenin signaling pathway associated with CHOP expression induced by ER stress, the induced CHOP disrupts the ß-catenin/TCF4 complex and represses the Wnt targeted genes. This study provides an alternative strategy for rational drug development to target Wnt/ß-catenin signaling pathway.

Overcoming cancer risk in inflammatory bowel disease: new insights into preventive strategies and pathogenesis mechanisms including interactions of immune cells, cancer signaling pathways, and gut microbiota.

Inflammatory bowel disease (IBD), characterized primarily by gastrointestinal inflammation, predominantly manifests as Crohn's disease (CD) and ulcerative colitis (UC). It is acknowledged that Inflammation plays a significant role in cancer development and patients with IBD have an increased risk of various cancers. The progression from inflammation to carcinogenesis in IBD is a result of the interplay between immune cells, gut microbiota, and carcinogenic signaling pathways in epithelial cells. Long-term chronic inflammation can lead to the accumulation of mutations in epithelial cells and the abnormal activation of carcinogenic signaling pathways. Furthermore, Immune cells play a pivotal role in both the acute and chronic phases of IBD, contributing to the transformation from inflammation to tumorigenesis. And patients with IBD frequently exhibit dysbiosis of the intestinal microbiome. Disruption of the gut microbiota and subsequent immune dysregulation are central to the pathogenesis of both IBD and colitis associated colorectal cancer (CAC). The proactive management of inflammation combined with regular endoscopic and tumor screenings represents the most direct and effective strategy to prevent the IBD-associated cancer.

Effects of resveratrol on lipid metabolism in liver of red tilapia Oreochromis niloticus.

Resveratrol (RES), as a polyphenol natural plant extract, mainly accumulates in the root of Polygonum cuspidatum, which can alleviate liver injury in mammals. Our study aims to explore the effects and potential mechanism of RES on lipid metabolism of red tilapia, and the effects of RES on liver structure, fat synthesis and metabolism of red tilapia were determined. The present study designed four groups named as 8 % fat (8%CK), 10 % fat (10 % HF), 10 % HF + RES and 10 % HF + RES + EX527 (selisistat). The liver tissues of red tilapia were collected at 3 (3 W), 6 (6 W) and 9 (9 W) weeks for parameter determination. Compared to the normal diet group, the hepatocyte of tilapia showed nuclear shift and vacuoles of different sizes when fed a high-fat diet. Meanwhile, the high-fat diet increased the contents of LDL, TC and TG significantly at 6 W, and significantly decreased the content of NAD+ at 9 W. Compared to the high-fat group, the nuclei of tilapia fed with RES were increased and visible, the degree of steatosis and the number of vacuoles were both reduced. At 3/6/9 W, RES significantly decreased the contents of LDL, TG and TMAO, and significantly increased the content of NAD+. A total of 1416 genes were up-regulated and 1928 genes were down-regulated in the group with added RES when compared to the 10 % HF group. The pathways related to lipid metabolism including PPAR signaling pathway have been enriched. Interestingly, the expressions of sirt1, pparα, fabp7 and cpt1b genes were up-regulated in RES diet group, while the expressions of pparγ, me1, scd and lpl genes were down-regulated. After the addition of an inhibitor (EX527), the above indexes showed an opposite trend when compared to the group with added RES. The overall results showed that the high-fat diet could cause fatty liver lesions in the liver of red tilapia, and RES could activate the sirt1 gene, regulate the PPARα/γ pathway and related genes, and thus regulate liver fat synthesis and metabolism leading to the alleviation of damage to liver tissue.

Remodeling Chondroitin-6-Sulfate-Mediated Immune Exclusion Enhances Anti-PD-1 Response in Colorectal Cancer with Microsatellite Stability.

Metastatic microsatellite-stable (MSS) colorectal cancer rarely responds to immune checkpoint inhibitors (ICI). Metabolism heterogeneity in the tumor microenvironment (TME) presents obstacles to antitumor immune response. Combining transcriptome (The Cancer Genome Atlas MSS colorectal cancer, n = 383) and digital pathology (n = 96) analysis, we demonstrated a stroma metabolism-immune excluded subtype with poor prognosis in MSS colorectal cancer, which could be attributed to interaction between chondroitin-6-sulfate (C-6-S) metabolites and M2 macrophages, forming the "exclusion barrier" in the invasive margin. Furthermore, C-6-S derived from cancer-associated fibroblasts promoted co-nuclear translocation of pSTAT3 and GLI1, activating the JAK/STAT3 and Hedgehog pathways. In vivo experiments with C-6-S-targeted strategies decreased M2 macrophages and reprogrammed the immunosuppressive TME, leading to enhanced response to anti-PD-1 in MSS colorectal cancer. Therefore, C-6-S-induced immune exclusion represents an "immunometabolic checkpoint" that can be exploited for the application of combination strategies in MSS colorectal cancer ICI treatment.

A bibliometric analysis of long non-coding RNA and chemotherapeutic resistance research.

The global outputs of annual publication in long non-coding RNAs (lncRNAs) and chemotherapeutic resistance research exponentially increased from 2 in 2008 to 176 in 2017. Using Java application CiteSpace V and VOSviewer, this study assessed the publication model of lncRNAs and chemoresistance by bibliometric analysis. Totally, 2883 authors contributed 528 publications of lncRNAs and chemoresistance in 215 academic journals in the recent decade (2008-2018). Oncotarget in the 215 academic journals published the highest number of publications (60). China had the highest number of publication outputs (358). The leading institute was Nanjing Medical University. Wang Y was the most influential author (13 counts). Gupta RA had the most cited documents (87 counts). "Gene expression" and "poor prognosis" were identified as the hotspots. "Cancer stem cell", "HOTAIR" and "UCA1" were the frontiers of the fields in recent years. The increase of publications on lncRNAs and chemotherapeutic resistance will continue in the next years. HOTAIR and UCA1 with multiple roles in drug resistance may offer big opportunities for targeted chemoresistance in cancer therapy. These results may help us discover and explain the possible underlying laws of the subject.

Inhibitory effects of the ultrasound-targeted microbubble destruction-mediated herpes simplex virus-thymidine kinase/ganciclovir system on ovarian cancer in mice.

The aim of the present study was to investigate the effect of the ultrasound-targeted microbubble destruction mediated (UTMD) herpes simplex virus-thymidine kinase (HSV-TK) and ganciclovir (GCV) system on ovarian cancer (OC). This study was conducted between June and December 2012 in the Animal Biosafety Level III Laboratory of Wuhan University. Mice with OC were randomly divided into four groups: i) HSV-TK plus microbubbles (MBs) plus ultrasound (US) (n=15); ii) HSV-TK plus US (n=15); iii) HSV-TK (n=15); and iv) phosphate-buffered saline (n=15). The inhibitory effect and survival time in the experimental groups were compared with those in the control group. The TK protein expression was detected by western blot analysis. Tumor cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling and caspase-3 activity analysis. The data showed that the efficiency of HSV-TK gene transfection and the tumor inhibitory effects were significantly increased in the HSV-TK plus MBs plus US group compared with those in the control group (P<0.01). UTMD-mediated HSV-TK treatment has also improved the rat survival rate (P<0.01). In conclusion, UTMD can effectively transfect the HSV-TK gene into target tissues and exert a significant inhibitory effect on OC in mice.

Roles of p38 MAPK and JNK in TGF-ß1-induced human alveolar epithelial to mesenchymal transition.

BACKGROUND AND AIMS: Idiopathic pulmonary fibrosis (IPF) is associated with significant morbidity and mortality despite aggressive therapy. The aim of the present study is to investigate the roles of p38 MAPK and JNK in TGF-ß1-induced human alveolar epithelial to mesenchymal transition (EMT), which could be a possible mechanism of IPF. METHODS: A549 cells were treated with TGF-ß1 (3 ng/mL) for 48 h to induce EMT. The expression of mesenchymal phenotypic markers including desmin, α-smooth muscle actin (α-SMA) and vimentin, and expression of epithelial phenotypic markers including E-cadherin, zonula occludens-1 (ZO-1) and aquaporin-5 (AQP5) were detected by Western blot. The roles of p38 MAPK and JNK in TGF-ß1-mediated EMT were investigated using gene silencing and inhibitor SB-203580 and SP-600125. RESULTS: The data showed that TGF-ß1 induced A549 cells with an alveolar epithelial type II cell phenotype to undergo EMT. The process of EMT was accompanied by morphological alteration and expression of the myofibroblast marker desmin, α-SMA and vimentin, concomitant with a downregulation of the epithelial cell marker E-cadherin, ZO-1 and AQP5. TGF-ß1-induced EMT occurred through phosphorylation of p38 MAPK and JNK and was inhibited by inhibitor SB-203580 and SP-600125 and gene silencing. CONCLUSIONS: TGF-ß1 induces A549 alveolar epithelial cells (AECs) to undergo EMT partially via p38 MAPK and JNK activation and supports the concept of EMT in lung epithelial cells.

[Comparative effect of different media in in vitro cultivation of Trichomonas vaginalis].

OBJECTIVE: To investigate the optimal condition for in vitro cultivation of Trichomonas vaginalis for obtaining a better harvest of T. vaginalis. METHODS: An isolate of T. vaginalis from clinical specimens was cultivated in three different media with initial inoculation of 9.0 x 10(4)/ml under pH 5.6. RESULTS: There was distinct difference after 96 h incubation in the cumulative harvest of T. vaginalis. The highest harvest was received in cysteine/liver/peptone/maltose medium, followed by the liver/peptone/maltose medium and soybean/liver/peptone/maltose medium. CONCLUSION: The cysteine/liver/peptone/maltose medium may be a suitable environment for in vitro multiplication of T. vaginalis.