Nasopharyngeal carcinoma (NPC) is a malignant tumor that mainly occurs in East and Southeast Asia. Although patients benefit from the main NPC treatments (e.g., radiotherapy and concurrent chemotherapy), persistent and recurrent diseases still occur in some NPC patients. Therefore, investigating the pathogenesis of NPC is of great clinical significance. In the present study, replication factor c subunit 4 (RFC4) is a key potential target involved in NPC progression via bioinformatics analysis. Furthermore, the expression and mechanism of RFC4 in NPC were investigated in vitro and in vivo. Our results revealed that RFC4 was more elevated in NPC tumor tissues than in normal tissues. RFC4 knockdown induced G2/M cell cycle arrest and inhibited NPC cell proliferation in vitro and in vivo. Interestingly, HOXA10 was confirmed as a downstream target of RFC4, and the overexpression of HOXA10 attenuated the silencing of RFC4-induced cell proliferation, colony formation inhibition, and cell cycle arrest. For the first time, this study reveals that RFC4 is required for NPC cell proliferation and may play a pivotal role in NPC tumorigenesis.
Humans ; Nasopharyngeal Carcinoma/pathology* ; Carcinoma/pathology* ; Replication Protein C/metabolism* ; Nasopharyngeal Neoplasms/pathology* ; Cell Line, Tumor ; Cell Proliferation ; Gene Expression Regulation, Neoplastic ; Cell Movement

OBJECTIVETo investigate the inhibitory effect of compound cantharides capsules on the proliferation of xenografts of human hepatocellular carcinoma HepG(2215) in mice and their mechanism of action.

METHODSOne hundred healthy Balb/c mice (5-week old, male:female 1:1) were used in this study. Mouse models of human HepG(2215) hepatocarcinoma were established. The tumor-bearing mice were divided into five groups randomly. The control group A received daily intragastric administration of physiologic saline. The intervention groups B1, B2 and B3 were treated with compound cantharides capsule in a dose of 12.5 mg×kg(-1)×d(-1), 25 mg×kg(-1)×d(-1) and 37.5 mg×kg(-1)×d(-1), respectively, for 10 consecutive days. The group C had intraperitoneal injection of cyclophosphamide (25 mg×kg(-1)×d(-1)) for 10 consecutive days. The mice were sacrificed after the completion of administration. The tumors were taken out, the tumor volume was measured, the inhibitory rate of body weight was calculated, and the serum AFP concentration and the level of HBV DNA were determined. The survival of each group mice was analyzed. The levels of mRNA expression of apoptosis-related genes were assayed by quantitative RT-PCR. Apoptosis in the tumor cells was assayed with TUNEL staining. Flow cytometry was used to detect the levels of CD3(+), CD19(+), CD4(+) and CD8(+), and microvessel density (MVD) of the tumors was assessed by immunohistochemistry.

RESULTSAfter completion of the treatment, the inhibition rate of tumor growth of the groups B1, B2 and B3 was 29.8%, 38.7% and 48.1%, respectively, and that of the group C was 52.4%, with a significant difference among the groups (P < 0.05). The median survival time of the groups A, B1, B2, B3 and C was (30.0 ± 3.2) days, (49.0 ± 5.1) days, (50.0 ± 5.2) days, (57.5 ± 6.5) days and (49.0 ± 4.7) days, respectively. The median survival time of the group B3 was significantly longer than that of other groups (P < 0.05). The serum AFP level in the groups A, B1, B2, B3 and C was (492.7 ± 48.5) ng/ml, (281.2 ± 25.6) ng/ml, (194.3 ± 18.7) ng/ml, (170.1 ± 15.8) ng/ml and (138.7 ± 12.5) ng/ml, respectively, indicating that it was significantly inhibited in the group C. The inhibition rate of HBV DNA replication of the groups B1, B2, B3 and C was (46.0 ± 5.1)%, (65.5 ± 6.9)%, (81.3 ± 7.8)% and (19.5 ± 2.1)%, respectively, showing that compound cantharides capsules inhibited HBV DNA replication in a dose-dependent manner. The apoptosis rate of the groups A, B1, B2, B3 and C was (0.27 ± 0.03)%, (7.18 ± 2.12)%, (9.17 ± 2.42)%, (11.27 ± 3.03)% and (5.44 ± 2.45)%, respectively, and that of the group B3 was significantly higher than that of the groups A, B1, B2 and C (P < 0.05). The expression level of bax mRNA was significantly higher than that of the group C (P < 0.05). The drug could significantly decrease the bcl-2 mRNA expression level, more remarkably along with the increasing dose of cantharides, and it was significantly lower than that in the group C (P < 0.05). The levels of CD4(+), CD8(+), CD3(+) and CD19(+) were significantly higher than that in the groups A and C (P < 0.05). The value of MVD of the group B3 was significantly lower that that of groups A and C (P < 0.05).

CONCLUSIONCompound cantharides capsules may inhibit the replication of HBV DNA in HepG(2215) cells, inducing apoptosis in the tumor cells, enhancing the immune function to inhibit the growth of liver cancer cells in mice, and significantly prolong the median survival time of tumor-bearing mice.

Animals ; Antineoplastic Agents ; administration & dosage ; pharmacology ; Antiviral Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Cantharidin ; administration & dosage ; pharmacology ; Capsules ; DNA Replication ; DNA, Viral ; Drug Combinations ; Female ; Hep G2 Cells ; Hepatitis B virus ; Humans ; Male ; Mice ; Mice, Inbred BALB C ; Microvessels ; pathology ; Neoplasm Transplantation ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Tumor Burden ; drug effects ; Virus Replication ; Xenograft Model Antitumor Assays ; alpha-Fetoproteins ; metabolism ; bcl-2-Associated X Protein ; genetics ; metabolism

Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.
Animals ; Antiviral Agents ; pharmacology ; therapeutic use ; Betacoronavirus ; drug effects ; physiology ; Binding Sites ; drug effects ; Cell Line ; Coronavirus Infections ; drug therapy ; virology ; Crotonates ; pharmacology ; Cytokine Release Syndrome ; drug therapy ; Drug Evaluation, Preclinical ; Gene Knockout Techniques ; Humans ; Influenza A virus ; drug effects ; Leflunomide ; pharmacology ; Mice ; Mice, Inbred BALB C ; Orthomyxoviridae Infections ; drug therapy ; Oseltamivir ; therapeutic use ; Oxidoreductases ; antagonists & inhibitors ; metabolism ; Pandemics ; Pneumonia, Viral ; drug therapy ; virology ; Protein Binding ; drug effects ; Pyrimidines ; biosynthesis ; RNA Viruses ; drug effects ; physiology ; Structure-Activity Relationship ; Toluidines ; pharmacology ; Ubiquinone ; metabolism ; Virus Replication ; drug effects