Anticancer effect of cucurbitacin B on MKN-45 cells via inhibition of the JAK2/STAT3 signaling pathway

The aim of the present study was to investigate the effect of cucurbitacin B on MKN-45 gastric carcinoma cells. Cell proliferation was determined using a cell counting kit-8 assay, and commercial cell cycle and apoptosis analysis kits were used to determine the cell cycle by flow cytometry. The mRNA expression of genes which mediate cell cycle checkpoints and apoptosis was detected using reverse transcription-quantitative polymerase chain reaction, and a terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to determine apoptosis rate. Western blot analysis was used to detect the protein expression levels of JAK2/STAT3 signaling pathway-associated proteins. The presented data show that cucurbitacin B significantly inhibited the proliferation of MKN-45 cells in a dose- and time-dependent manner. In accordance with these findings, cucurbitacin B blocked the progression of the cell cycle from G0/G1 to S phase, which was confirmed by the mRNA expression analysis. Cucurbitacin B treatment significantly suppressed the expression of cyclin D1, cyclin E, cyclin-dependent kinase 4 (CDK4) and CDK2, while increasing the expression of p27. Cucurbitacin B also promoted cell apoptosis, as was determined by TUNEL assay and evaluation of mRNA expression. Further experiments suggested that the beneficial effect of cucurbitacin B on blocking the proliferation and inducing the apoptosis of MKN-45 cells may have been associated with suppression of the JAK2/STAT3 signaling pathway. Thus, the present results indicate that cucurbitacin B suppresses proliferation and promoted apoptosis of MKN-45 cells, which may be mediated by inhibition of the JAK2/STAT3 signaling pathway. Cucurbitacin B therefore may warrant further investigation as a feasible therapy for gastric carcinoma.

Insulin promotes sinusoidal endothelial cell proliferation mediated by upregulation of vascular endothelial growth factor in regenerating rat liver after partial hepatectomy

AIM: To determine whether insulin could promote sinusoidal endothelial cell (SEC) proliferation mediated by upregulation of vascular endothelial growth factor (VEGF) in regenerating rat liver after partial hepatectomy (PHx).

METHODS: Adult male Sprague-Dawley rats undergoing 70% PHx were injected with insulin (300 MU/kg) or saline via the tail veins every 8 h after surgery for 7 d and killed at 0, 24, 48, 72, 96, 120, 144, and 168 h after surgery. Proliferation of both hepatocytes and SECs was monitored by evaluating the proliferating cell nuclear antigen (PCNA) labeling index (LI). The expression of VEGF protein was evaluated by immunohistochemistry. The mRNA expressions of VEGF and its receptors Flt-1 and Flk-1 were evaluated by semi-quantitative reverse transcription-PCR.

RESULTS: Insulin markedly increased the expression of VEGF mRNA between 24 and 120 h after hepatectomy compared to controls. Similarly, insulin significantly increased the expression of Flt-1 between 24 and 96 h. However, insulin had no significant effect on Flk-1. Furthermore, the immunohistochemical staining revealed that expression of VEGF protein increased in the insulin groups. Insulin significantly increased the PCNA LI of hepatocytes and SECs compared to controls.

CONCLUSION: Exogenous insulin may promote SEC proliferation with an enhanced expression of VEGF and its receptor Flt-1 inregenerating rat liver after PHx.

Expression of Survivin in pancreatic cancer and its correlation to expression of Bcl-2

AIM: To investigate the expression of Survivin in pancreatic cancer and its correlation to the expression of Bcl-2.

METHODS: Survivin and Bcl-2 expressions were examined by immunohistochemistry in 42 tissue samples from pancreatic cancer and 10 from normal pancrease.

RESULTS: No survivin expression was detected in the tissue samples from normal pancrease, while it was detected in 34 of 42 tissue samples from pancreatic cancer (81.95%). There was a correlation between survivin expression and differentiation and stages of pancreatic cancer. Survivin positive cases were strongly correlated to Bcl-2 expression (28/30 vs 6/12, P < 0.05).

CONCLUSION: Overexpression of survivin plays an important role in the development and progression of pancreatic cancer, and correlates to the expression of Bcl-2. Survivin expression can be used as a prognostic factor.

Toxicities and therapeutic effect of 5-fluorouracil controlled release implant on tumor-bearing rats

AIM: To investigate the toxicities, biodistribution and anticancer effect of 5-fluorouracil controlled release implant (5-FUCI) on Walker 256 carcinosarcoma cells in Wistar rats.

METHODS: Experiment 1: Wistar rats were randomly divided into three groups (27 rats per group). Blank implant was implanted in left lobe of the liver, and rats were treated with saline solution (in group A) or 5-fluorouracil (subcutaneous injection, group B). 5-FUCI was inserted in left lobe of the liver (group C). The gastrointestinal and hematological toxicities were observed and contents of element F in group C were assayed. Experiment 2: on day 6 after Walker-256 carcinosarcoma transplantation in left lobe of the liver, 5-FUCI was implanted in right lobe of the liver (group E) or left lobe (group F), and rats in control group (group D) were inserted blank implant. Tumor inhibition rate and survival time were investigated.

RESULTS: 5-FUCI showed no obvious toxic effect, extraction of Evan’s blue from gastrointestinal tissue was normal, the peripheral white blood cells and bone marrow nucleated cells were not reduced, compared with control group (P > 0.05). Histological examination revealed that there were no visible changes in small intestinal mucosa, The concentration of 5-fluorouracil in left lobe of the liver was 9.84, 28, 34 times as much as those of right lobe of the liver, heart and kidney respectively after the implantation in group C. They kept a high level of fluorouracil in left lobe of the liver, ranging from (4.414% ± 0.482%) to (7.800% ± 0.804%), for eight weeks. Survival days were 28.0 ± 2.2, 30.0 ± 3.2 and 38.7 ± 6.7 d in group D, E and F, respectively.

CONCLUSION: 5-FUCI shows no obvious toxicities to gastrointestinal tract and myelotoxicity. After implantation, it kept a high level of 5- fluorouracil in surrounding tissues of the implant for eight weeks. Its antitumor effect on Walker-256 carcinosarcoma is demonstrated.

Relationship between nuclear morphometry, DNA content and resectability of pancreatic cancer

AIM: To investigate the association of nuclear morphometry and DNA content with resectability of pancreatic cancer.

METHODS: A total of 36 patients with pancreatic adenocarcinoma were divided into resectable group and unresectable group. The nuclear morphometry and DNA contents of tumor cells were analyzed by IBAS autoimagine analyzer from paraffin-embedded materials. Localization size, histological type and grade, and clinical stage of the tumor were evaluated. Factors influencing resectability of pancreatic cancer were investigated using stepwise regression analysis.

RESULTS: Statistical significance was found in nuclear DNA content (integrated optical density, IOD) of tumor cells (1.64 ± 0.41 vs 2.96 ± 0.55), DNA ploidy, ages (46.5 ± 5.3 years vs 58.6 ± 0.7 years) and tumor volumes (298.1 ± 101.5 cm³vs 634.7 ± 512.5 cm³) in both groups (P < 0.05), and no difference was found in the nuclear morphometry (P > 0.05). The rates of diploid/tetraploid and aneuploid were 66.7% and 33.3% in resectable group respectively, and 38.9% and 62.1% in unresectable group, respectively (P < 0.05). IOD (X₁₂), ploidy status (X₁₃) and clinical stage (X₃) were radical resectable indicators with statistical significance. The regression equation for resectability was Y = -9.2053 + 3.5428X₁₂ + 2.5390X₁₃ - 2.3001X₃ (RR = 0.8780, P < 0.01).

CONCLUSION: There is a high correlation between resectability of pancreatic cancers and their DNA contents, DNA ploidy status and clinical stage.

Tamoxifen combined with octreotide or regular chemotherapeutic agents in treatment of primary liver cancer: a randomized controlled trial

OBJECTIVE

To evaluate the effect of tamoxifen (TAM) combined with a somatostatin analogue, octretide (OCT) on advanced liver cancer and whether tamoxifen combined with OCT is superior to regular chemotherapeutic agents 5-Fu and mitomycin C (MMC).

METHODS

Thirty-nine patients with inoperable liver cancer were randomly subdivided into TAM+OCT group (n=24) and regular chemotherapeutic group (n=15). They received treatment for three months respectively. Blood cell count, liver function, immunologic function, blood alpha-FP was regularly measured. Liver lump and extrahepatic metastasis were examined by CT. The patients were followed up after treatment and conducted survival analysis.

RESULTS

In the TAM+OCT group, complete response is 4 patients, partial response is 7 patients, no change is 9 patients and progressive disease is 4 patients; blood level of ALT and AST had no noticeable change, IgE and IgG increased (P<0.01), and alpha-FP lowered (P<0.05). In regular chemotherapeutic group, no change is 4 patients and progressive disease is 11 patients. There was conspicuous statistical difference in the two groups. The accumulative survival rates of 6 months, 1 year and 2 years were 95.7% vs 41.2% (P<0.01), 63.7% vs 21.1% (P<0.01), 25.4% vs 0 (P<0.01), respectively. Medium survival time was 12.8 months in TAM+OCT group and 5.5 months in chemotherapeutic group.

CONCLUSIONS

TAM+OCT excerts reliable therapeutic effect on patients with inoperable ER(+) hepatocellular cancer. It is superior to 5-Fu and MMC in increasing the survival rate, prolonging survival time, and reducing side-effects.