Tumors cells with mismatch repair deficiency induce hyperactivation of pyroptosis resistant to cell membrane damage but are more sensitive to co-treatment of IFN-γ and TNF-α to PANoptosis.

Hypermutated neoantigens in cancers with DNA mismatch repair deficiency (dMMR) are prerequisites for favorable clinical responses to immune-checkpoint blockade (ICB) therapy. However, TMB is not significantly associated with favorable prognosis from Preclinical and clinical studies. It implies that except for TMB, other mechanisms should be needed to contribute to successful cancer immunotherapy. We found that the hyperactivation of PANoptotic effective molecules in dMMR tumor cells caused cell membrane damage, induced ESCRT-mediated membrane repair, and protected tumor cells from the damage caused by Triton X-100, while DNA mismatch repair proficient (pMMR) tumor cells were sensitive to Triton X-100 mediating cell membrane damage due to the lack of ESCRT-mediated membrane repair. There was hyperactivation of GSDMD, GSDME, and p-MLKL in dMMR tumor cells. Co-treatment of IFN-γ and TNF-α induced rapid death of dMMR tumor cells by inducing PANoptosis including pyroptosis, apoptosis, and no necrosis. pMMR tumor cells had defects in the PANoptosis pathway and were resistant to co-treatment of IFN-γ and TNF-α. In conclusion, we can activate immune cells to release IFN-γ and TNF-α to overcome resistance to ICB treatment.

EphB6 deficiency in intestinal neurons promotes tumor growth in colorectal cancer by neurotransmitter GABA signaling.

EphB6 belongs to the receptor tyrosine kinase, whose low expression is associated with shorter survival of colorectal cancer (CRC) patients. But the role and mechanism of EphB6 in the progression of CRC need further study. In addition, EphB6 was mainly expressed in intestinal neurons. But how EphB6 is involved in functions of intestinal neurons has not been known. In our study, we constructed a mouse xenograft model of CRC by injecting CMT93 cells into the rectum of EphB6-deficient mice. We found that the deletion of EphB6 in mice promoted tumor growth of CMT93 cells in a xenograft model of CRC, which was independent of changes in the gut microbiota. Interestingly, inhibition of intestinal neurons by injecting botulinum toxin A into rectum of EphB6-deficient mice could eliminate the promotive effect of EphB6 deficiency on tumor growth in the xenograft model of CRC. Mechanically, the deletion of EphB6 in mice promoted the tumor growth in CRC by increasing GABA in the tumor microenvironment. Furthermore, EphB6 deficiency in mice increased the expression of synaptosomal-associated protein 25 in the intestinal myenteric plexus, which mediated the release of GABA. Our study concluded that EphB6 knockout in mice promotes tumor growth of CMT93 cells in a xenograft model of CRC by modulating GABA release. Our study found a new regulating mechanism of EphB6 on the tumor progression in CRC that is dependent on intestinal neurons.

A novel form of docetaxel polymeric micelles demonstrates anti-tumor and ascites-inhibitory activities in animal models as monotherapy or in combination with anti-angiogenic agents.

Malignant ascites (MA) is caused by intraperitoneal spread of solid tumor cells and results in a poor quality of life. Chemotherapy is a common first-line treatment for patients with MA. Taxotere ® (DTX) is widely used in solid tumor therapies. However, the low water solubility and side effects caused by additives in the formulation restrict the clinical application of docetaxel. HT001 is a clinical stage docetaxel micelle developed to overcome the solubility issue with improved safety profiles. To support clinical development and expand clinical application of HT001, this study used in vitro and in vivo approaches to investigate the anti-tumor effects of HT001 when applied as monotherapy or in combination with anti-angiogenic agents. HT001 demonstrated comparable anti-proliferative activities as docetaxel in a broad range of cancer cell lines in vitro. Furthermore, HT001 suppressed tumor growth in a dose-dependent manner in A549, MCF-7, and SKOV-3 xenograft tumor mouse models in vivo. In a hepatocellular carcinoma H22 malignant ascites-bearing mouse model, HT001 presented a dose-dependent inhibition of ascites production, prolonged animal survival, and reduced VEGF levels. When dosed at 20 mg/kg, the HT001-treated group exhibited curative results, with no ascites formation in 80% of mice at the end of the study while all the mice in the vehicle control group succumbed. Similar results were obtained in HT001 treatment of mice bearing malignant ascites produced by human ovarian cancer ES-2 cells. Notably, the combination of HT001 with Endostar not only significantly reduced ascites production but also prolonged survival of H22 ascites-bearing mice. HT001 showed similar PK and tissue distribution profiles as DTX in non-rodent hosts. Collectively, these results demonstrate potent anti-tumor activity of HT001 in multiple solid tumor models or malignant ascites models, and reveal synergistic effects with anti-angiogenic agents, supporting the clinical development and clinical expansion plans for HT001.

Diosgenin inhibits the epithelial-mesenchymal transition initiation in osteosarcoma cells via the p38MAPK signaling pathway.

Diosgenin is an important basic raw material for the production of steroid hormone drugs. It can be isolated and purified from a variety of traditional Chinese medicines or plants. Modern molecular biological studies have shown that diosgenin inhibits various tumor cells migration and invasion ability to varying degrees in vitro and in vivo. The aim of the present study was to observe the inhibitory effects of diosgenin on the invasive and metastatic capabilities of osteosarcoma cells and to determine the association between the effects of diosgenin on the epithelial-mesenchymal transition (EMT). Wound healing and Transwell assays were used to observe the inhibitory effects of diosgenin on the invasion and migration of two osteosarcoma cell lines. Immunofluorescence was used to observe changes in transforming growth factor ß1 (TGF-ß1) protein expression levels in the osteosarcoma cells following drug administration. EMT-associated proteins, including TGFß1, E-cadherin and vimentin were detected by western blotting, which demonstrated that the drug may inhibit the initiation of EMT in osteosarcoma cells. Western blot analysis of the expression of all the proteins in the mitogen-activated protein kinase (MAPK) pathway demonstrated that the drug inhibited the MAPK signaling pathway. The primary mechanism of action of diosgenin was the inhibition of the phosphorylated p38 (pP38) protein. Through a combination of inhibitors of the p38MAPK signaling pathway and detection of the downstream EMT marker protein E-cadherin by quantitative PCR, pP38 was confirmed to be a target of diosgenin in the inhibition of EMT in the osteosarcoma cells via the MAPK molecular signaling pathway. Diosgenin may exhibit utility as an auxiliary drug for the clinical reduction of metastasis in patients with osteosarcoma.

Astragaloside IV inhibits the invasion and metastasis of SiHa cervical cancer cells via the TGF­ß1­mediated PI3K and MAPK pathways.

Astragaloside IV is the main ingredient of the medicinal herb Radix astragali, which has reported to have antitumor activity in vitro and in vivo. To determine whether the inhibitory effect of astragaloside IV on the invasion and metastasis of the cervical cancer cells is associated with epithelial­mesenchymal transition (EMT), wound healing and Transwell assays were performed using SiHa cervical cancer cells and demonstrated that astragaloside IV inhibited invasion and migration of human SiHa cervical cancer cells in vitro. Immunocytochemical and western blot analyses indicated that astragaloside IV inhibited EMT by affecting the expression of transforming growth factor­ß1 (TGF­ß1) and E­cadherin in the cancer cells. Two Smad­independent pathways mediated by TGF­ß1 were identified to be associated with the effects of astragaloside IV, namely, mitogen­activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PI3K) signaling pathways. The data indicated that astragaloside IV has inhibitory effects on phosphorylation of P38 MAPK, PI3K, AKT and mTOR of SiHa cells of cervical cancer. Furthermore, MAPK and PI3K pathway inhibitors were administered to the cancer cells and the expression of E­cadherin, a marker of EMT, was determined by reverse transcription­quantitative polymerase chain reaction. The results demonstrated that MAPK and PI3K pathways were involved in the inhibitory effect of astragaloside IV on EMT. In vivo small animal imaging techniques was performed and demonstrated that astragaloside IV inhibited the metastasis of cervical cancer cells. Taken together, the findings demonstrated that astragaloside IV inhibits the invasion and migration of cervical cancer cells in vitro and in vivo.

Diosgenin­induced autophagy and apoptosis in a human prostate cancer cell line.

Diosgenin, a plant steroid compound from Dioscorea nipponica, is an anti-inflammatory, antidiabetic, antitumor, vasodilatory compound, which also reduces blood lipid content and protects against ischemia­induced neuronal damage. However, a limited number of studies have been performed on the antitumor effect of diosgenin on prostate cancer, the underlying mechanism of which remains to be fully elucidated. In the present study, the effect and underlying mechanism of diosgenin on DU145 human prostate cancer cells was investigated. DU145 cells were cultured in vitro with diosgenin, following which cell proliferation was detected by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and apoptosis was detected by flow cytometry. In addition, DU145 cells were observed under a transmission electron microscope to confirm autophagy. monodansylcadaverine staining and western blotting indicated the levels of autophagy in DU145 cells. To determine the mechanism underlying the effect of diosgenin on DU145 cells, western blotting was performed to evaluate the involvement of the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. To investigate the association between apoptosis and autophagy, DU145 cells were cultured with diosgenin and 3­methyladenine. Hoechst 33342/propidium iodide double staining was performed to detect apoptosis, and reverse transcription­quantitative polymerase chain reaction was used to analyze mRNA expression levels of Beclin 1 and B­cell lymphoma 2. Diosgenin inhibits the proliferation of DU145 cells by activating apoptosis and autophagy, and the mechanism underlying this activation may be associated with the inhibition of the PI3K/Akt/mTOR signaling pathway. In addition, the inhibition of autophagy mediated by diosgenin increases apoptosis and, thus, increases the therapeutic effect. The combination of diosgenin with an autophagy inhibitor may be an effective strategy to increase the antitumor effect of diosgenin.

Reduction of apoptosis by proanthocyanidin-induced autophagy in the human gastric cancer cell line MGC-803.

Proanthocyanidins are flavonoids that are widely present in the skin and seeds of various plants, with the highest content in grape seeds. Many experiments have shown that proanthocyanidins have antitumor activity both in vivo and in vitro. Autophagy and apoptosis of tumor cells induced by drugs are two of the major causes of tumor cell death. However, reports on the effect of autophagy induced by drugs in tumor cells are not consistent and suggest that autophagy can have synergistic or antagonistic effects with apoptosis. This research was aimed at investigating whether proanthocyanidins induced autophagy and apoptosis in human gastric cancer cell line MGC-803 cells and to identify the mechanism of proanthocyanidins action to further determine the effect of proanthocyanidins-induced autophagy on apoptosis. MTT assay was used to examine the proanthocyanidin cytotoxicity against human gastric cancer cell line MGC-803. Transmission electron microscopy and monodansylcadaverine (MDC) staining were used to detect autophagy. Annexin V APC/7-AAD double staining and Hoechst 33342/propidium iodide (PI) double staining were used to explore apoptosis. Western blotting was used to determine expression of proteins related to autophagy and apoptosis. Real-time quantitative PCR technology was used to determine the mRNA level of Beclin1 and BCL-2. The results showed that proanthocyanidins exhibit a significant inhibitory effect on the human gastric cancer cell line MGC-803 proliferation in vitro and simultaneously activate autophagy and apoptosis to promote cell death. Furthermore, when proanthocyanidin-induced autophagy is inhibited, apoptosis increases significantly, proanthocyanidins can be used together with autophagy inhibitors to enhance cytotoxicity.