Induction of cell cycle arrest and apoptosis by 5-fluorouracil in laryngeal cancer cells containing HPV16 E6 and E7 oncoproteins

Case report of recurrent spontaneous tumor lysis syndrome in a patient with esophageal cancer recovered via chemotherapy

Tumor lysis syndrome (TLS) is a life-threatening oncological emergency. Only one TLS case has been reported in patients with esophageal cancer. We report the case of a 61-year-old man with recurrent spontaneous TLS caused by esophageal cancer. He was admitted to our hospital to investigate low back pain and dysphagia. Endoscopy and computed tomography revealed esophageal cancer with multiple liver and bone metastases. He was diagnosed with laboratory TLS based on high serum uric acid and phosphorus. After intravenous fluids and allopurinol were administrated, chemotherapy with 5-fluorouracil and cisplatin was started the next day. Although he transiently developed clinical TLS, it was resolved with conservative treatment. However, mild renal dysfunction was prolonged and cisplatin was reduced in the second course. As a consequence, recurrence of spontaous TLS (sTLS) was induced at the end of the course. In the third course, docetaxel was added to the regimen, and since then the patient have not develop sTLS. To the best of our knowledge, this is the first report regarding recurrent sTLS developed on the basis of solid tumors and was successfully controlled by chemotherapy. Although TLS complications are rare in esophageal cancer, early diagnosis and the adjustment of regimen resulted in stable chemotherapy.

HPV16 E6 promotes cell proliferation, migration, and invasion of human cervical cancer cells by elevating both EMT and stemness characteristics

In most cases of cervical cancer, the high-risk of the disease is caused by the human papilloma virus (HPV). Surgery or radiation usually benefits patients with early cervical cancer, while the metastatic one is uncurable and new therapeutic strategies and approaches are required. In this study, HPV16 E6 silence or overexpression were carried out to evaluate the possible mechanisms of HPV16 E6 function in cervical cancer cells with different HPV16 E6 expression background. HPV16 E6-positive cervical cancer cell Siha exerts significantly stronger cell invasion and migration potentials than the HPV16 E6-negative C33A cells. HPV16 E6 silence significantly weakened the potentials of cell invasion and migration, cell proliferation and stemness characteristic in Siha cells. Meanwhile, the overexpression of HPV16 E6 effectively promoted the cell proliferation and stemness characteristic in C33A cells. Our data also indicated a positive association between HPV16 E6 and the levels of epithelial to mesenchymal transition (EMT), and cell stemness. The ectopic expression of OCT4 could effectively reverse the inhibitory roles of HPV16 E6 silence on cell migration, invasion, and stemness in Siha cells. More interestingly, we found that HPV16 E6 might promote the OCT4 expression by impairing the direct binding of p53 on the promoter and activate its transcription. Taken together, our results indicated that HPV16 E6 could promoted the potential cell proliferation, migration, and invasion of human cervical cancer cells by modulating EMT and cell stemness. Our data provide a novel mechanism for how HPV16 E6 acts as a key risk factor for cervical cancer development and progression. This article is protected by copyright. All rights reserved.

DNMT1 Enhances the Radiosensitivity of HPV-Positive Head and Neck Squamous Cell Carcinomas via Downregulating SMG1

Introduction

Head and neck squamous cell carcinoma (HNSCC), which rank the 7th malignant tumors worldwide, is closely related to methylation and HPV infection. Ionizing radiation therapy is the main strategy for HNSCC patients in advanced stage. Previously, HPV-positive HNSCC predict better prognosis than HPV-negative HNSCCs under radiotherapy, however its molecular mechanism is unresolved. SMG1 serves as a potential tumor suppressor in various cancers, including HNSCC.

Methods

The mRNAs and proteins expression of HPV E6/E7, p16, p53, DNMT1, SMG1 were detected after different treatments by qPCR and Western blot. The clone formation ability was measured in radiation dose after different treatments.

Results

In our study, the expression of HPV16 E6, DNA Methyltransferase 1(DNMT1) and SMG1 in head and neck carcinomas cell lines was detected by RT-qPCR and Western blot. Forced E6 level in HPV-negative cells by overexpression plasmid promoted the expression of DNMT1, which resulted in decreased SMG1 expression. Silenced SMG1 in HPV-negative HNSCC cells elicited increased radiation sensitivity, suggesting that SMG1 may be an effective switch to regulate the effect of radiotherapy in HNSCC.

Conclusion

Our study indicated that DNMT1 enhances the radiosensitivity of HPV-positive head and neck squamous cell carcinomas via downregulating SMG1.

Anticancer activity of grassy Hystrix brachyura bezoar and its mechanisms of action: An in vitro and in vivo based study

Porcupine bezoar (PB) is a calcified undigested material generally found in porcupine's (Hystrix brachyura) gastrointestinal tract. The bezoar is traditionally used in South East Asia and Europe for the treatment of cancer, poisoning, dengue, typhoid, etc. However, limited scientific studies have been performed to verify its anticancer potential to substantiate its traditional claims in the treatment of cancers. Hence, this study was aimed at investigating the in vitro and in vivo anticancer properties of two grassy PB aqueous extract (PB-A and PB-B) using A375 cancer cell line and zebrafish model, respectively. This paper presents the first report on in vitro A375 cell viability assay, apoptosis assay, cell cycle arrest assay, migration assay, invasion assay, qPCR experimental assay and in vivo anti-angiogenesis assay using the grassy PBs. Experimental findings revealed IC₅₀ value are 26.59 ± 1.37 μg/mL and 30.12 ± 3.25 μg/mL for PB-A and PB-B respectively. PBs showed anti-proliferative activity with no significant cytotoxic effect on normal human dermal fibroblast (NHDF). PBs were also found to induce apoptosis via intrinsic pathway and arrest cell cycle at G2/M phase. Additionally, the findings indicated its ability to debilitate migration and invasion of A375 cells. Further evaluation using embryo zebrafish model revealed LC₅₀ = 450.0 ± 2.50 μg/mL and 58.7 ± 5.0 μg/mL for PB-A and PB-B which also exerted anti-angiogenesis effect in zebrafish. Moreover, stearic acid, ursodeoxycholic acid and pregnenolone were identified as possible metabolites that might contribute to the anticancer effect of the both PBs. Overall, this study demonstrated that PB-A and PB-B possess potential in vitro and in vivo anticancer effects which are elicited through selective cytotoxic effect, induction of apoptosis, inhibition of migration and invasion and anti-angiogenesis. This study provides scientific evidence that the porcupine bezoar do possess anti-cancer efficacy and further justifies its traditional utility. However, more experiments with higher vertebrae models are still warranted to validate its traditional claims as an anticancer agent.