Phenylethanol glycosides from Herba Cistanche improve the hypoxic tumor microenvironment and enhance the effects of oxaliplatin via the HIF‑1α signaling pathway

Liensinine sensitizes colorectal cancer cells to oxaliplatin by targeting HIF-1α to inhibit autophagy

BACKGROUND

Oxaliplatin is the most common chemotherapeutic agent for patients with colorectal cancer. However, its anti-cancer efficacy is restricted by drug resistance occurring through several mechanisms, including autophagy. Liensinine exerts a considerable anti-tumor effect and can regulate autophagy. Inhibition of autophagy is a strategy to reverse resistance to oxaliplatin. The aim of this study was to check if liensinine can enhance the therapeutic efficacy of oxaliplatin in colorectal cancer and if so, elucidate its mechanism.

METHODS

Two colorectal cancer cell lines, HCT116 and LoVo, and one normal intestinal epithelial cell, NCM-460 were used for in vitro experiments. Cell Counting Kit-8 (CCK-8), colony formation, and flow cytometry assays were used to evaluate the cytotoxicity of liensinine and oxaliplatin. Network pharmacology analysis and Human XL Oncology Array were used to screen targets of liensinine. Transfections and autophagy regulators were used to confirm these targets. The relationship between the target and clinical effect of oxaliplatin was analyzed. Patient-derived xenograft (PDX) models were used to validate the effects of liensinine and oxaliplatin.

RESULTS

CCK-8 and colony formation assays both showed that the combination treatment of liensinine and oxaliplatin exerted synergistic effects. Results of the network pharmacology analysis and Human XL Oncology Array suggested that liensinine can inhibit autophagy by targeting HIF-1α/eNOS. HIF-1α was identified as the key factor modulated by liensinine in autophagy and induces resistance to oxaliplatin. HIF-1α levels in tumor cells and prognosis for FOLFOX were negatively correlated in clinical data. The results from three PDX models with different HIF-1α levels showed their association with intrinsic and acquired resistance to oxaliplatin in these models, which could be reversed by liensinine.

CONCLUSIONS

Research on the relationship between HIF-1α levels and the clinical effect of oxaliplatin is lacking, and whether liensinine regulates HIF-1α is unknown. Our findings suggest that liensinine overcomes the resistance of colorectal cancer cells to oxaliplatin by suppressing HIF-1α levels to inhibit autophagy. Our findings can contribute to improving prognosis following colorectal cancer therapy.

Exercise performance reduction and preventive measures in highland sports

The plateau is a special environment with low pressure, low oxygen, low temperature, and high ultraviolet radiation. The exercise performance of people on the plateau is generally reduced, which seriously affects the life and health of people living in the plateau and entering the plateau. In recent years, the prevention and treatment of injury caused by high altitude hypoxia has attracted wide attention. It has shown that the higher the altitude with the longer the duration of exercise, the faster the stationing, the greater the impact on people's sports performance. Rapid entry into the plateau and long-term stay in the plateau have an impact on people's explosive power, endurance and fine operation. Advances in medical technology enable various prevention methods to be used to acclimate to high altitude environments. However, in vitro intervention methods are costly, easy to rebound and possess limited effects. Therefore, drug prevention and treatment is obviously a more economical choice. Chemical drugs increase the efficiency of high altitude exercise by improving the ischemic and hypoxic symptoms of the heart and brain, increasing lung ventilation and arterial oxygenation capacity, and accelerating the elimination of adverse product accumulation after exercise. Single Chinese medicine, Chinese patent medicine, and compound preparations can improve exercise performance by promoting body metabolism, improving muscle endurance, enhancing immunity, and other mechanisms. Traditional Chinese medicine has unique advantage and application prospect in improving plateau sports performance damage.

Effect of PhenylEthanol Glycosides from Cistanche Tubulosa on Autophagy and Apoptosis in H22 Tumor-Bearing Mice

An effectual remedy for hepatocellular carcinoma (HCC) and knowledge of the mechanism are urgently needed. Researchers have found that CPhGs, an extract from Cistanche tubulosa (Schenk) Wight, had better antitumor effects, but its mechanism is still unknown. In the present study, using an H22 tumor-bearing mouse as a model, we investigated the antitumor effects of CPhGs and the effect of CPhGs on autophagy and apoptosis. Besides, we also discussed the role of autophagy with the help of HCQ and rapamycin. Our results show that CPhGs inhibit tumor growth and induce apoptosis and autophagy of tumor tissue. TUNEL staining displayed that tumor apoptosis rate increased after the intervention of CPhGs, and immunohistochemistry and western blot showed that cleaved-PARP and cleaved-caspase 3 were upregulated after the intervention of CPhGs, and these results were most pronounced in the high-dose group. Autophagy results revealed that CPhGs increased the number of autophagosomes, increased the level of LC3B-II, and decreased the level of p62. Finally, our results showed that excessive autophagy suppresses tumor growth, whereas inhibition of autophagy does the opposite, which indicated that CPhGs induced autophagic death in H22 hepatoma-bearing mice. These data altogether confirmed the involvement of apoptosis and autophagy in CPhGs treatment for HCC.

Network Pharmacology and Molecular Docking Analysis on Molecular Targets and Mechanisms of Bushen Hugu Decoction in the Treatment of Malignant Tumor Bone Metastases

Purpose. To explore the active compounds of the Chinese medicine prescriptions of Bushen Hugu Decoction (BHD) and demonstrate its mechanisms against malignant tumor bone metastasis (BM) through network pharmacology and molecular docking analysis.Methods. The main components and targets of BHD were retrieved from the TCMSP database, and the targets were normalized by UniProt. The Herbs-Components-Targets network of BHD was established by Cytoscape. The main BM targets were obtained from GeneCards, TTD, DrugBank, and OMIM. STRING and Cytoscape were used to construct a PPI network and obtain hub genes. DAVID and Metascape were used for GO and KEGG enrichment analyses. According to the network topology parameters, the top 4 components were selected for molecular docking verification with the core targets. Results. Compound–target network of BHD mainly contained 51 compounds and 259 corresponding targets including 107 BHD-BM targets. PPI interaction network and subnetworks identified ten hub genes. GO enrichment analysis found 1970 terms ( $p<0.05$ ), and 164 signaling pathways ( $p<0.05$ ) were found in KEGG, including PI3K-Akt signaling pathway, proteoglycans in cancer, prostate cancer, MAPK signaling pathway, and IL-17 signaling pathway. Molecular docking analysis showed that the active components of BHD, quercetin, luteolin, kaempferol, and aureusidin have good binding activity to the core targets. Conclusion. The potential molecular target and signaling pathways were found for BHD major active components. It provides guidance for the future mechanism research of the BHD in malignant tumor bone metastasis. This study also established the foundation for the new strategy for the pharmacology study of Chinese medicine.

HOTAIR/miR-1277-5p/ZEB1 axis mediates hypoxia-induced oxaliplatin resistance via regulating epithelial-mesenchymal transition in colorectal cancer

The hypoxic microenvironment contributes to the chemoresistance of many malignant tumors including colorectal cancer (CRC). Accumulating studies have indicated that long non-coding RNAs (lncRNAs) play important roles in chemotherapy resistance. In this study, we aimed to determine the effect of lncRNAs in hypoxia-mediated resistance in CRC and its potential mechanism. Here, we discovered that hypoxia-induced oxaliplatin resistance and HOX transcript antisense RNA (HOTAIR) expression was increased in hypoxia-treated CRC cell lines and CRC tumors. Knockdown of HOTAIR by siRNA reduced the viability and proliferation of CRC cells treated with oxaliplatin and reversed hypoxia-induced resistance. Mechanically, we found that HOTAIR modulates zinc finger E-box binding homeobox 1 (ZEB1) expression by negative regulations of miR-1277-5p. When miR-1277-5p was silenced, knockdown of HOTAIR was unable to reduce the oxaliplatin resistance in CRC cells. In mouse models of CRC, HOTAIR knockdown markedly inhibited the tumor growth when treated with oxaliplatin. Thus, HOTAIR/miR-1277-5p/ZEB1 axis appears a promising therapeutic target for improving the oxaliplatin efficacy in CRC.