Shuai Lin

Antitumor effects of rapamycin in pancreatic cancer cells by inducing apoptosis and autophagy.

Rapamycin (Rapa), an inhibitor of mammalian target of Rapamycin (mTOR), is an immunosuppressive agent that has anti-proliferative effects on some tumors. This study aims to investigate the effects of Rapa suppressing proliferation of pancreatic carcinoma PC-2 cells in vitro and its molecular mechanism involved in antitumor activities. MTT assays showed that the inhibition of proliferation of PC-2 cells in vitro was in a time- and dose-dependent manner. By using transmission electron microscopy, apoptosis bodies and formation of abundant autophagic vacuoles were observed in PC-2 cells after Rapa treatment. Flow cytometry assays also showed Rapa had a positive effect on apoptosis. MDC staining showed that the fluorescent density was higher and the number of MDC-labeled particles in PC-2 cells was greater in the Rapa treatment group than in the control group. RT-PCR revealed that the expression levels of p53, Bax and Beclin 1 were up-regulated in a dose-dependent manner, indicating that Beclin 1 was involved in Rapa induced autophagy and Rapa induced apoptosis as well as p53 up-regulation in PC-2 cells. The results demonstrated that Rapa could effectively inhibit proliferation and induce apoptosis and autophagy in PC-2 cells.

Anti-angiogenic effect of the total flavonoids in Scutellaria barbata D. Don

BackgroundAngiogenesis is closely related to the growth, invasion and metastasis of tumors, also considered as the key target of anticancer therapy. Scutellaria barbata D. Don (S. barbata), a traditional Chinese medicine, is being used to treat various diseases, including cancer. However, the antitumor molecular mechanism of S. barbata was still unclear. This study aimed to investigate the inhibitory effects of the total flavones in S. barbata (TF-SB) on angiogenesis.MethodsHuman umbilical vein endothelial cells (HUVECs) were treated with various concentrations of TF-SB. Cell viability was examined using the MTT assay. The scratch assay was used to detect the migration of HUVECs after treatment with TF-SB. The ability of HUVECs to form network structures in vitro was demonstrated using the tube formation assay. The chick embryo chorioallantoic membrane assay was performed to detect the in vivo anti-angiogenic effect. The expression of VEGF was measured by the enzyme-linked immunosorbent.ResultsResults showed that TF-SB inhibited the proliferation and migration of HUVECs in a dose- dependent manner. Simultaneously, TF-SB significantly suppressed HUVEC angiogenesis in vitro and in vivo. Furthermore, VEGF was downregulated in both HUVECs and MHCC97-H cells after TF-SB treatment.ConclusionTF-SB could suppress the process of angiogenesis in vitro and in vivo. TF-SB potentially suppresses angiogenesis in HUVECs by regulating VEGF. These findings suggested that TF-SB may serve as a potent anti-angiogenic agent.

Targeted inhibition of mammalian target of rapamycin (mTOR) enhances radiosensitivity in pancreatic carcinoma cells

The mammalian target of rapamycin (mTOR) is a protein kinase that regulates protein translation, cell growth, and apoptosis. Rapamycin (RPM), a specific inhibitor of mTOR, exhibits potent and broad in vitro and in vivo antitumor activity against leukemia, breast cancer, and melanoma. Recent studies showing that RPM sensitizes cancers to chemotherapy and radiation therapy have attracted considerable attention. This study aimed to examine the radiosensitizing effect of RPM in vitro, as well as its mechanism of action. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation assay showed that 10 nmol/L to 15 nmol/L of RPM had a radiosensitizing effects on pancreatic carcinoma cells in vitro. Furthermore, a low dose of RPM induced autophagy and reduced the number of S-phase cells. When radiation treatment was combined with RPM, the PC-2 cell cycle arrested in the G2/M phase of the cell cycle. Complementary DNA (cDNA) microarray and reverse transcription polymerase chain reaction (RT-PCR) revealed that the expression of DDB1, RAD51, and XRCC5 were downregulated, whereas the expression of PCNA and ABCC4 were upregulated in PC-2 cells. The results demonstrated that RPM effectively enhanced the radiosensitivity of pancreatic carcinoma cells.

Sonodynamic therapy (SDT): A novel treatment of cancer based on sonosensitizer liposome as a new drug carrier

Cancer is a major cause of morbidity and mortality. Chemotherapy is one of the main means of cancer treatment. Conventional chemotherapy agents kill rapidly proliferating cells, resulting in some of the most common side effects of chemotherapy. Liposome-encapsulated drugs offer the possibility to increase target efficacy as well as reducing toxic side effects of chemotherapeutic drugs. However, the target specificity of liposome is dissatisfied. We urgently need to develop new approaches to improving drug target efficacy. Recently, sonodynamic therapy (SDT) of cancer, which is based on preferential uptake and retention of a sonosensitizer in tumor tissues and subsequent activation of drug by ultrasound radiation, is a developing field. In this article, we propose the use of sonosensitizers in combination with liposome to target chemotherapy drugs directly to tumor cells. SDT with low-intensity ultrasound combined with a sonosensitizer may be a promising approach to cancer therapy.

RUNX3 gene promoter demethylation by 5-Aza-CdR induces apoptosis in breast cancer MCF-7 cell line

Runt-related transcription factor 3 (RUNX3) is a tumor suppressor gene, its inactivation due to hypermethylation related to carcinogenesis. The aim of this study was to investigate the effects of 5-aza-2′-deoxycytidine (5-Aza-CdR) on cell proliferation and apoptosis by demethylation of the promoter region and restoring the expression of RUNX3 in the breast cancer MCF-7 cell line. MCF-7 cells were cultured with different concentrations (0.4–102.4 μmol/L) of 5-Aza-CdR in vitro. MTT assay was used to determine the proliferation of MCF-7 cells. Flow cytometry and Hoechst staining were used for analyzing cell apoptosis. The methylation status and expression of RUNX3 in mRNA and protein levels were measured by methylation-specific polymerase chain reaction (PCR [MSP]), reverse transcription (RT)-PCR, and Western blot. It was shown that the RUNX3 gene downregulated and hypermethylated in MCF-7 cells. 5-Aza-CdR induced demethylation, upregulated the expression of RUNX3 on both mRNA and protein levels in cancer cells, and induced growth suppression and apoptosis in vitro in a dose- and time-dependent manner. The results demonstrate that RUNX3 downregulation in breast cancer is frequently due to hypermethylation, and that 5-Aza-CdR can inhibit cell proliferation and induce apoptosis by eliminating the methylation status of RUNX3 promoter and restoring its expression.

The effect of RHIZOMA COPTIDIS and COPTIS CHINENSIS aqueous extract on radiation-induced skin injury in a rat model

BackgroundRadiation-induced skin injury is a common complication of radiotherapy. The RHIZOMA COPTIDIS and COPTIS CHINENSIS aqueous extract (RCE) can ameliorate radiation-induced skin injury in our clinical observation. But, the protective mechanism of RHIZOMA COPTIDIS and COPTIS CHINENSIS in radiation-induced skin injury remains unclear.MethodsIn this experiment, we developed a radiation-induced skin injury rat model to study the mechanism. The animals were randomly divided into control group, treatment group, radiation group, and treatment and radiation group. 5 rats in each group were separately executed on 2 d and 49 d post-radiation. The semi-quantitative skin injury score was used to measure skin reactions by unblinded observers, and hematoxylin and eosin staining was used to evaluate the damage areas by irradiation. The MDA content, SOD activity of skin and serum were measured to detect the oxidative stress.ResultsAcute skin reactions were caused by a single dose of 45 Gy of β-ray irradiation, and the skin injury could be found in all rats receiving irradiation based on the observation of HE staining of skin at different time-points, while RCE could significantly ameliorate those changes. The MDA content in serum and skin of control rats was 4.13 ± 0.12 mmol/ml and 4.95 ± 0.35 mmol/mgprot on 2 d post-radiation. The rats receiving radiation showed an increased content of MDA (5.54 ± 0.21 mmol/ml and 7.10 ± 0.32 mmol/mgprot), while it was 4.57 ± 0.21 mmol/ml and 5.95 ± 0.24 mmol/mgprot after treated with RCE (p < 0.05). Similar changes of the MDA content could be seen on 49 d post-radiation. However, the SOD activity of rats receiving radiation decreased compared with control group on both time-points, which was inhibited by RCE (p < 0.05). Meanwhile, no valuable changes could be found between control group and treatment group on 2 d and 49 d.ConclusionsOur study provides evidences for the radioprotective role of RCE against radiation-induced skin damage in rats by modulating oxidative stress in skin, which may be a useful therapy for radiation-induced skin injury.

Protective effects of Scutellaria barbata against rat liver tumorigenesis.

Scutellaria barbata D. Don (S. barbata), a traditional Chinese medicine, is used to treat cancers, inflammation, and urinary diseases. This study aimed to determine any protective effects of S. barbata crude extract (CE-SB) against rat liver tumorigenesis induced by diethylnitrosamine (DENA). Liver malfunction indices in serum were measured by biochemical examination. Hematoxylin and eosin staining was performed to examine liver pathology. Contents of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured in liver homogenates to evaluate oxidative stress. The levels of liver malfunction indices in the CE-SB groups, especially in the CE-SB high dose group, were lower than that of the model group (P<0.05). The results from histological examination indicated that the number of liver nodules in the CE-SB groups decreased compared with the model group (P<0.05). Content of MDA determined in liver was significantly decreased, and level of SOD elevated by CE-SB. CE-SB can inhibit experimental liver tumorigenesis and relieve hepatic injury in rats.

Prognostic and predictive values of PD-L1 expression in patients with digestive system cancer: a meta-analysis

Background PD-L1 has been reported to be expressed in diverse human malignancies. However, the prognostic value of PD-L1 in digestive system cancers remains inconclusive. Therefore, we conducted this meta-analysis to evaluate the prognostic impact of PD-L1 expression in digestive system cancers. Materials and methods We searched the PubMed, Embase, and the Chinese National Knowledge Infrastructure for publications concerning PD-L1 expression in digestive system cancers. Correlations of PD-L1 expression level with overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS) were analyzed. Results Finally, 32 studies with 7,308 patients were included. Our results show that PD-L1 expression was significantly associated with poorer OS (hazard ratio [HR] =1.44, 95% confidence interval [CI] =1.18–1.76, P<0.001), but not DFS (HR =0.91, 95% CI =0.61–1.37, P=0.657) or RFS (HR =1.27, 95% CI =0.75–2.14, P=0.368). Moreover, in the subgroup analysis, significant associations between PD-L1 expression and OS were found in Asians (HR =1.50, 95% CI =1.19–1.89, P=0.001), gastric cancer (HR =1.43, 95% CI =1.05–1.94, P=0.021), and pancreatic carcinoma (HR =2.64, 95% CI =1.78–3.93, P<0.001). Conclusion These results suggest that the expression of PD-L1 is associated with worse OS in digestive system cancers, especially in gastric cancer and pancreatic cancer. In addition, PD-L1 may act as a new parameter for predicting poor prognosis and a promising target for anticancer therapy in digestive system cancers.

Esophageal Cancer With Esophageal Duplication Cyst

Esophageal duplication cysts are benign, asymptomatic anomalies of foregut formation. We report a case of esophageal duplication cyst with esophageal squamous cancer. An upper endoscopy visualized with esophageal scan disclosed a stenotic lesion in the lower esophagus. Computed tomography images revealed a cystic mass in the inferior mediastinum, which was on the right wall of the esophagus. The postoperative pathology report confirmed the diagnosis of esophageal squamous cancer (ulcer type) and esophageal duplication cyst with calcification.