Intratumor Mycoplasma promotes the initiation and progression of hepatocellular carcinoma.

The carcinogenesis and progression of hepatocellular carcinoma (HCC) are closely related to viral infection and intestinal bacteria. However, little is known about bacteria within the HCC tumor microenvironment. Here, we showed that intratumoral Mycoplasma hyorhinis (M. hyorhinis) promoted the initiation and progression of HCC by enhancing nuclear ploidy. We quantified M. hyorhinis in clinical tissue specimens of HCC and observed that patients with high M. hyorhinis load had poor prognosis. We found that gastrointestinal M. hyorhinis can retrogradely infect the liver through the oral-duodenal-hepatopancreatic ampulla route. We further found that the increases in mononuclear polyploidy and cancer stemness resulted from mitochondrial fission caused by intracellular M. hyorhinis. Mechanistically, M. hyorhinis infection promoted the decay of mitochondrial fusion protein (MFN) 1 mRNA in an m6A-dependent manner. Our findings indicated that M. hyorhinis infection promoted pathological polyploidization and suggested that Mycoplasma clearance with antibiotics or regulating mitochondrial dynamics might have the potential for HCC therapy.

Erratum: Targeting myeloid-derived suppressor cells to attenuate vasculogenic mimicry and synergistically enhance the anti-tumor effect of PD-1 inhibitor.

[This corrects the article DOI: 10.1016/j.isci.2021.103392.].

Biomimetic Immunosuppressive Exosomes that Inhibit Cytokine Storms Contribute to the Alleviation of Sepsis.

Sepsis is a disease characterized by multiple organ failure caused by immune hyperactivation and cytokine storms. Studies have shown that the incidence of sepsis in melanoma patients is substantially lower compared to the general population. It is also observed that experimental tumor-bearing animals have high survival rates after sepsis induction, suggesting that tumors may suppress sepsis-associated immune overactivation, thereby alleviating sepsis. Based on the above-described findings, this work assesses whether tumor cells play an antisepsis role in mice through the secretion of exosomes. Analysis of exosome activity reveals that the induced exosomes (iExo) secreted by tumor cells following lipopolysaccharide (LPS) treatment improve sepsis to a greater extent than normal secretory exosomes. Further analysis reveals that iExo exert their protective effects mainly through seven key miRNAs. In vitro bionic simulation of exosomes is carried out using exosome mimics generated by loading the aforementioned microRNAs into hyaluronic acid-polyethylenimine nanoparticles. Exosome mimics at specific miRNA ratios alleviate sepsis in mice and cynomolgus monkeys, indicating that biomimetic simulation of tumor-suppressive exosomes may represent a promising therapeutic method for the treatment of sepsis and cytokine-storm-related conditions.

Pinin Induces Epithelial-to-Mesenchymal Transition in Hepatocellular Carcinoma by Regulating m6A Modification.

Pinin is a moonlighting protein localized in desmosomes and nucleus. It could promote the growth of hepatocellular carcinoma. Whether this protein can induce epithelial-to-mesenchymal transition (EMT) and malignant progression in HCC is unknown. This work found that Pinin prompts EMT in vitro and in vivo. Further mechanism study found that Pinin increases the level of N6-methyladenosine (m6A) modification of RNA by interacting with METTL3, which in turn induces snail1 expression. These findings suggest that Pinin induces EMT by regulating m6A modification and, thus, could be a potential anticancer target for HCC therapy.

Targeting myeloid-derived suppressor cells to attenuate vasculogenic mimicry and synergistically enhance the anti-tumor effect of PD-1 inhibitor.

Myeloid-derived suppressor cells (MDSCs) enhance the proliferation of endothelial cells to stimulate angiogenesis. However, many aggressive malignant tumors do not have endothelial cell-dependent blood vessels in the early stage and instead generate microcirculation by forming vasculogenic mimicry (VM). To date, the relationship between MDSCs and tumor cells remains the focus of ongoing studies. In this work, MDSCs were co-cultured with mouse melanoma cells and can enhance proliferation and VM formation of melanoma cells. For MDSCs targeting, doxycycline (DOX) was found to selectively suppress PMN-MDSCs but has no influence on T cells. In addition, DOX pretreatment substantially reduced the promoting ability of MDSCs for the VM formation of B16-F10 cells. DOX also inhibited tumor growth and enhanced the antitumor activity of PD-1 inhibitors in C57BL6 and BALB/c mice subcutaneously inoculated with B16-F10 and 4T1 cells, respectively. In conclusion, the combination of DOX and PD-1 inhibitor could be an anticancer strategy.

RNA m6A methylation promotes the formation of vasculogenic mimicry in hepatocellular carcinoma via Hippo pathway.

Vasculogenic mimicry (VM) formed by aggressive tumor cells to mimic vasculogenic networks plays an important role in the tumor malignancy of HCC. However, the pathogenesis underlying VM is complex and has not been fully defined. m6A is a common mRNA modification and has many biological effects. However, the relationship between m6A and VM remains unclear. In this research, we found that m6A methyltransferase METTL3 in HCC tissues was positively correlated with VM. The m6A level of mRNA significantly increased in 3D cultured cells treated with VEGFa and was related to VM formation. Transcriptome sequencing analysis of 3D cultured cells with knockdown Mettl3 showed that the Hippo pathway was involved in m6A-mediated VM formation. Further mechanism research indicated that the m6A modification of YAP1 mRNA affected the translation of YAP1 mRNA. In conclusion, m6A methylation plays a key role in VM formation in HCC. METTL3 and YAP1 could be potential therapeutic targets via impairing VM formation in anti-metastatic strategies.

Targeted Drug-Loaded Chemical Probe Staining Assay to Predict Therapy Response and Function as an Independent Pathological Marker.

Multi-targeted kinase inhibitors, such as sorafenib, have been used in various malignancies, but their efficacy in clinical applications varies among individuals and lacks pretherapeutic prediction measures. We applied the concept of "click chemistry" to pathological staining and established a drug-loaded probe staining assay. We stained the cells and different types of pathological sections and demonstrated that the assay was reliable. We further verified in cells, cell-derived xenograft model, and clinical level that the staining intensity of the probe could reflect drug sensitivity. The stained samples from 300 patients who suffered from hepatocellular carcinoma and used the sorafenib probe also indicated that staining intensity was closely related to clinical information and could be used as an independent marker without undergoing sorafenib therapy for prognosis. This assay provided new ideas for multi-target drug clinical trials, pre-medication prediction, and pathological research.

USP5 promotes epithelial-mesenchymal transition by stabilizing SLUG in hepatocellular carcinoma.

Rationale: The role of SLUG in epithelial-mesenchymal transition during tumor progression has been thoroughly studied, but its precise regulation remains poorly explored. Methods: The affinity purification, mass spectrometry and CO-IP were performed to identify the interaction between SLUG and ubiquitin-specific protease 5 (USP5). Cycloheximide chase assays and deubiquitination assays confirmed that the effect of USP5 on the deubiquitin of SLUG. The dual-luciferase reporter and chromatin immunoprecipitation assays were employed to observe the direct transcriptional regulation of E-cadherin by SLUG effected by USP5. EMT related markers was detected by western blotting and immunofluorescence. Molecular docking, SPR sensor (biacore) and co-location were detected to prove Formononetin targets USP5. Bioinformatics analysis was used to study the relation of USP5 and SLUG to malignancy degree of HCC. Cell migration, invasion in HCC cells and xenografts model in nude mouse were conducted to detect the promotion of USP5 and the inhibition of Formononetin on EMT. Results: USP5 interacts with and stabilizes SLUG to regulate its abundance through USP5 deubiquitination activities in epithelial-mesenchymal transition (EMT) of hepatocellular carcinoma (HCC). USP5 is highly expressed and positively correlated with SLUG expression in HCC with high malignancy. Knockdown of USP5 inhibits SLUG deubiquitination and inhibits HCC cells proliferation, metastasis, and invasion, while overexpression of USP5 promotes SLUG stability and EMT in vitro and in vivo. Through virtual screening, we found that Formononetin exhibits excellent binding to USP5. Moreover, Formononetin inhibits deubiquitinating activities of USP5 to SLUG and consequently impedes the EMT and malignant progression of HCC. Conclusion: Our findings reveal that USP5 serve as a potential target for tumor intervention and provide a preliminary antitumor therapy for inhibit EMT by targeting USP5 or its interaction with SLUG in HCC.

Salidroside improves the hypoxic tumor microenvironment and reverses the drug resistance of platinum drugs via HIF-1α signaling pathway.

BACKGROUND: Hypoxia commonly occurs in solid tumors. The hypoxia in the center of solid tumors considerably decreases the chemosensitivity of tumor cells and induces epithelial-mesenchymal transition (EMT) as well as drug resistance of antitumor drugs. METHODS: Here, the effects of salidroside (Sal) combined with platinum drugs on human hepatocellular carcinoma were examined in vitro and in vivo. We investigated the antitumor effects of Sal by inhibiting the drug resistance and explained its mechanism in inhibiting tumor growth. FINDINGS: The results showed that Sal co-administration reverses the drug resistance of platinum drugs and suppressed metastasis induced by the hypoxic tumor microenvironment. Sal promoted the degradation of HIF-1α. In conclusion, Sal significantly increased the sensitivity to platinum drugs and inhibited hypoxia-induced EMT in hepatocellular carcinoma (HCC) through inhibiting HIF-1α signaling pathway. INTERPRETATION: Therefore, Sal may be an effective platinum drug sensitizer that can improve the chemotherapeutic efficacy in patients with HCC.

Polyphyllin I suppresses the formation of vasculogenic mimicry via Twist1/VE-cadherin pathway.

Vasculogenic mimicry (VM) is a functional microcirculation pattern formed by aggressive tumor cells and is related to the metastasis and poor prognosis of many cancer types, including hepatocellular carcinoma (HCC). Thus far, no effective drugs have been developed to target VM. In this study, patients with liver cancer exhibited reduced VM in tumor tissues after treatment with Rhizoma Paridis. Polyphyllin I (PPI), which is the main component of Rhizoma Paridis, inhibited VM formation in HCC lines and transplanted hepatocellular carcinoma cells. Molecular mechanism analysis showed that PPI impaired VM formation by blocking the PI3k-Akt-Twist1-VE-cadherin pathway. PPI also displayed dual effects on Twist1 by inhibiting the transcriptional activation of the Twist1 promoter and interfering with the ability of Twist1 to bind to the promoter of VE-cadherin, resulting in VM blocking. This study is the first to report on the clinical application of the VM inhibitor. Results may contribute to the development of novel anti-VM drugs in clinical therapeutics.

Derepression of co-silenced tumor suppressor genes by nanoparticle-loaded circular ssDNA reduces tumor malignancy.

The co-silencing of multiple tumor suppressor genes can lead to escalated malignancy in cancer cells. Given the limited efficacy of anticancer therapies targeting single tumor suppressor genes, we developed small circular single-stranded DNA (CSSD) that can up-regulate the expression of co-silenced tumor suppressor genes by sequestering microRNAs (miRNAs) that negatively regulate these genes. We found that cancer patients with low tumor expression of the tumor suppressor genes KLF17, CDH1, and LASS2 had shortened survival times. The up-regulation of these genes upon transfection of artificial CSSD-9 inhibited tumor proliferation and metastasis and promoted apoptosis in vitro as well as in ex vivo and patient-derived xenograft models. In addition, CSSD is more stable and effective than current miRNA inhibitors, and transfecting CSSDs via nanoparticles substantially improved delivery efficiency. The use of a single CSSD can promote the inhibition of multiple tumor suppressor genes. This study provides evidence for the possibility of using CSSDs as therapeutic miRNA inhibitors to target the co-silencing of multiple tumor suppressor genes.

Dihydroartemisinin inhibits EMT induced by platinum-based drugs via Akt-Snail pathway.

Artemisinin and its derivatives exhibit a high activity against a range of cancer cell types both in vitro and in vivo. In clinical practice, platinum-based anti-cancer chemotherapy is widely used to treat tumors. However, a large proportion of patients receiving these treatments will relapse because of metastasis and drug resistance. The purpose of this study is to explore the combinational anti-metastatic effect of platinum-based drugs and dihydroartemisinin (DHA). Both DDP and oxaliplatin (OXA) at low doses could induce epithelial-mesenchymal transition (EMT) in HCC. Meanwhile, co-administration of DHA could enhance DDP and OXA chemosensitivity in HCC and reverse drug resistance. DHA reversed the morphological changes induced by DDP or OXA and reversed the changes in EMT biomarkers induced by DDP and OXA in HCC in vitro and in vivo via AKT-Snail signaling. DHA significantly increased platinum-based drug sensitivity and suppressed EMT induced by platinum-based drugs via AKT-Snail signaling in HCC. DHA is expected to become the new adjuvant for chemotherapy.

Sesquiterpene binding Gly-Leu-Ser/Lys-"co-adaptation pocket" to inhibit lung cancer cell epithelial-mesenchymal transition.

Sesquiterpene lactones (SL) have a wide range of applications in anti-tumor and anti-inflammatory therapy. However, the pharmacological mechanism of such substances is not clear. In this study, parthenolide (PTL) was used as an example to explore the anti-tumor effect of natural molecules and their common mechanism. We showed that PTL inhibited the proliferation and migration by reverse EMT via the ERK2/NF-κB/Snail pathway in vivo and in vitro. Interestingly, Multiple potential targets of PTL contain a Gly-Leu-Ser/Lys-"co-adaptation pocket". This inspiring us analogies of PTL may also bind to these target proteins and play a similar function. Significantly, the Concept of co-adaptation pocket may help to increase the selectivity of drug research and development.

Hsp90ß promoted endothelial cell-dependent tumor angiogenesis in hepatocellular carcinoma.

BACKGROUND: Vascular endothelial growth factor receptors (VEGFRs) are the major receptors involved in endothelial cell-dependent tumor angiogenesis. There are studies account for the effects of Hsp90 on angiogenesis, but the role and mechanism of Hsp90ß isoforms and NVP-BEP800, a specific inhibitor of Hsp90ß, in tumor angiogenesis is rarely mentioned. METHODS: Immunohistochemistry and statistical analysis was used to evaluate the correlation between Hsp90ß expression, CD31 endothelial cell-dependent vessel density, and VEGFRs expression in tissue samples of 96 HCCs. Kaplan-Meier survival analysis and COX proportional hazards analysis the relation of Hsp90ß and prognosis. HUVEC cells were transfected with Hsp90ß or treated with NVP-BEP800, and then cell proliferation, migration, invasion and tube formation were investigated. The VEGFR1 and VEGFR2 expression was determined by Western blot and immunofluorescence. The VEGFR1 and VEGFR2 promoter activities were detected by dual luciferase report system. In vivo, the angiogenesis promotion of Hsp90ß and anti-angiogenesis efficacy of NVP-BEP800 was tested in HCC xenograft models. Histological analysis was performed on tumor samples to evaluate Hsp90ß, VEGFRs expression and MVD. RESULTS: This study investigated the correlation between Hsp90ß expression and CD31+ endothelial cell-dependent vessel density. Hsp90ß promoted VEGFRs expression by increasing their promoter activities. The proliferation, migration, invasion, and tube formation activities of human endothelial cells significantly increased when Hsp90ß was overexpressed. NVP-BEP800 down-regulated VEGFRs expression to significantly reduce tubular differentiation, as well as endothelial cell proliferation, migration, and invasion. Furthermore, NVP-BEP800 decreased VEGFR1 and VEGFR2 promoter activities. In vivo, Hsp90ß promoted VEGFRs and CD31 expression in human hepatocellular carcinoma tumor xenografts and was associated with increased tumor microvessel density. After 18 days of treatment with 30 mg/kg/day NVP-BEP800, VEGFRs and CD31 expression significantly decreased. CONCLUSION: Hsp90ß induced endothelial cell-dependent tumor angiogenesis by activating VEGFRs transcription. NVP-BEP800 has potential as a therapeutic strategy for inhibiting tumor angiogenesis by decreasing endothelial cell progression and metastasis. It can help develop a therapeutic strategy for tumor treatment through the inhibition of endothelial cell progression and metastasis.