[Application of bevacizumab on metastatic breast cancer].

Tumor angiogenesis defines tumor growth as it is dependent on generation of new blood vessels. Over forty years ago, Folkman hypothesized that inhibiting tumor angiogenesis could inhibit the growth of solid tumors and thus could be exploited as a therapeutic strategy. Among the numerous factors have been implicated in the angiogenesis activation process, vascular endothelial growth factor (VEGF) is the best studied angiogenesis target in cancer, using many different approaches in a wide variety of human cancers. Bevacizumab is the first anti-VEGF monoclonal antibody and proof-of-concept angiogenesis inhibitor that has been approved by the United States FDA for several tumor types. Drugs inhibiting VEGF work through several mechanisms, including inhibition of tumor blood vessel growth, vascular renormalization, potentiating of other antitumor agents, and inhibiting tumor metastasis. Unlike colorectal, kidney, lung, and brain tumors, the use of bevacizumab in breast cancer has been, as it were, on a rollercoaster in the United States, from accelerated approval for early drug access by patients in February 2008, to modest efficacy that fell short of high expectations, and increasing concern for serious toxicity in July 2010, and on to FDA revocation of accelerated approval for metastatic breast cancer patients in November 2011. Through a concise review of the FDA process, we have summarized its lessons, the challenges in developing new cancer drugs, and perspectives on further development of bevacizumab and other angiogenesis inhibitors in treatment of breast cancer. Despite all the challenges, antiangiogenesis remains a promising strategy to conquer breast cancer.

Predictive Value of Pin1 in Cervical Low-Grade Squamous Intraepithelial Lesions and Inhibition of Pin1 Exerts Potent Anticancer Activity against Human Cervical Cancer.

Many oncogenes are involved in the progression from low-grade squamous intraepithelial lesions (LSILs) to high-grade squamous intraepithelial lesions (HSILs); which greatly increases the risk of cervical cancer (CC). Thus, a reliable biomarker for risk classification of LSILs is urgently needed. The prolyl isomerase Pin1 is overexpressed in many cancers and contributes significantly to tumour initiation and progression. Therefore, it is important to assess the effects of cancer therapies that target Pin1. In our study, we demonstrated that Pin1 may serve as a biomarker for LSIL disease progression and may constitute a novel therapeutic target for CC. We used a the novel Pin1 inhibitor KPT-6566, which is able to covalently bind to Pin1 and selectively target it for degradation. The results of our investigation revealed that the downregulation of Pin1 by shRNA or KPT-6566 inhibited the growth of human cervical cancer cells (CCCs). We also discovered that the use of KPT-6566 is a novel approach to enhance the therapeutic efficacy of cisplatin (DDP) against CCCs in vitro and in vivo. We showed that KPT-6566-mediated inhibition of Pin1 blocked multiple cancer-driving pathways simultaneously in CCCs. Furthermore, targeted Pin1 treatment suppressed the metastasis and invasion of human CCCs, and downregulation of Pin1 reversed the epithelial-mesenchymal transition (EMT) of CCCs via the c-Jun/slug pathway. Collectively, we showed that Pin1 may be a marker for the risk of progression to HSIL and that inhibition of Pin1 has anticancer effects against CC.

[Effect of protein kinase C/transforming growth factor beta 1 pathway on activation of hepatic stellate cells].

OBJECTIVE: To investigate the effect of protein kinase C (PKC)/transforming growth factor beta 1 (TGF beta1) pathway on activation of hepatic stellate cells (HSC). METHODS: HSC rHSC-99 cell line was used in three groups in this study. Group A served as a control. In group B the HSC were incubated with PKC agonist PMA (0.5 micromol/L), and in group C the cells were incubated with PKC inhibitor calphostin C (100 nmol/L). The PKC activities were detected at different incubation time points (0, 3, 6, 12 and 24 h). Western blot and RT-PCR were used to detect the expression of TGF beta1, Smad 4, collagen type I, III and alpha-smooth muscle actin (alpha-SMA) at the 24 h point. Cell proliferation was assessed by MTT colorimetric assay. RESULTS: PMA increased the activity of PKC significantly, whereas calphostin C inhibited the activity of PKC. The increased activity of PKC promoted the HSC to express TGF beta1, Smad 4, collagen type I, III and alpha-SMA. In comparison with the controls, the expressions of TGF beta1, Smad 4, collagen type I, III and alpha-SMA increased 4.8, 13.1, 2.4, 1.8 and 1.3 fold respectively (P < 0.01). PKC promoted the proliferation of HSC. The above effects were inhibited by the inhibition of PKC activity. CONCLUSION: Changing of PKC activity can regulate and control the expression of TGF beta1, which may play a role in regulating the activation of HSC.

Effect of ligand of peroxisome proliferator-activated receptor gamma on the biological characters of hepatic stellate cells.

AIM: To study the effect of rosiglitazone, which is a ligand of peroxisome proliferator-activated receptor gamma (PPARgamma), on the expression of PPARgamma in hepatic stellate cells (HSCs) and on the biological characteristics of HSCs. METHODS: The activated HSCs were divided into three groups: control group, 3 micromol/L rosiglitazone group, and 10 micromol/L rosiglitazone group. The expression of PPARgamma, alpha-smooth muscle actin (alpha-SMA), and type I and III collagen was detected by RT-PCR, Western blot and immunocytochemical staining, respectively. Cell proliferation was determined with methylthiazolyltetrazolium (MTT) colorimetric assay. Cell apoptosis was demonstrated with flow cytometry. RESULTS: The expression of PPARgamma at mRNA and protein level markedly increased in HSCs of 10 micromol/L rosiglitazone group (t value was 10.870 and 4.627 respectively, P<0.01 in both). The proliferation of HSCs in 10 micromol/L rosiglitazone group decreased significantly (t = 5.542, P<0.01), alpha-SMA expression level and type I collagen synthesis ability were also reduced vs controls (t value = 10.256 and 14.627 respectively, P<0.01 in both). The apoptotic rate of HSCs significantly increased in 10 micromol/L rosiglitazone group vs control (chi(2) = 16.682, P<0.01). CONCLUSION: By increasing expression of PPARgamma in activated HSCs, rosiglitazone, an agonist of PPARgamma, decreases alpha-SMA expression and type I collagen synthesis, inhibits cell proliferation, and induces cell apoptosis.

[An in vivo study on interlukin-10 inhibiting the expression and secretion of collagen I and IV in hepatic stellate cells].

OBJECTIVES: To investigate the effect of interlukin-10 (IL-10) on expression and secretion of collagen I, IV in rat's hepatic stellate cells (HSC) of livers injured by CCl4. METHOD: The adenovirus vector encoded IL-10 gene was used to transfect rats with liver injury via the caudal veins. HSC were isolated and purified from the rat livers by collagenase IV perfusion and density gradient centrifugation with Nycodenz. The expression of collagen I, IV mRNA in HSC was detected by semi-quantitative RT-PCR method and the secretion of collagen I, IV in culture serum of HSC by ELISA method. The quantity of collagen was measured in the van Gieson stained histological liver preparations. RESULTS: The expression and secretion of collagen I, IV in the adenovirus vector encoding IL-10 gene group were significantly lower than those in the adenovirus vector without IL-10 gene group and the control group (P < 0.05). The quantity of collagen in the treatment group was lower than that in the control group. CONCLUSION: IL-10 can inhibit collagen I, IV expression and secretion in rat HSC.

[Downregulation of transforming growth factor-beta1 and platelet-derived growth factor gene expression by interleukin-10 in murine hepatic stellate cells in response to experimental liver injury].

OBJECTIVE: To investigate the effect of interleukin-10 (IL-10) on the expression of transforming growth factor-beta(1) (TGFbeta(1)) and platelet-derived growth factor (PDGF) in hepatic stellate cells (HSC) during liver injury. METHODS: The adenovirus vector (the titer was 1 x 10(7) efu/ml) encoded IL-10 gene was used to transfect the rat via the vein of caudal. At the same time, CCl(4) was injected into rat by a hypodermic injection. These processes went on twice a week. After eight weeks, the liver were perfused with collagenase IV and purified by density gradient centrifugation with Nycodenz for separate HSC. The level of IL-10 was measured by ELISA method; The expression of PDGF and TGFbeta(1) in HSC was detected by semi-quantitative RT-PCR and Western-blot methods. RESULTS: The level of IL-10 in therapy group (adenovirus vector encoding IL-10 gene group) was higher than that in non-therapy group (adenovirus vector without IL-10 gene and PBS group); The expression of TGFbeta(1) mRNA, TGFbeta(1) protein and PDGF mRNA, PDGF protein in therapy group were significantly lower than that in non-therapy group (P < 0.05). CONCLUSION: Downregulating the TGFbeta(1) and PDGF expression could be the passageway by which IL-10 alleviate the degree of proliferation and activation in hepatic stellate cells.

Peroxisome proliferator-activated receptor gamma ligands suppress liver carcinogenesis induced by diethylnitrosamine in rats.

AIM: Peroxisome proliferator-activated receptor gamma (PPARgamma) is known to regulate growth arrest and terminal differentiation of adipocytes and is used clinically as a new class of antidiabetic drugs. Recently, several studies have reported that treatment of cancer cells with PPARgamma ligands could induce cell differentiation and apoptosis, suggesting a potential application as chemopreventive agents against carcinogenesis. In the present study, 3 different kinds of PPARgamma ligands were subjected to the experiments to confirm their suppressive effects on liver carcinogenesis. METHODS: Three PPARgamma ligands, pioglitazone (Pio) (200 ppm), rosiglitazone (Rosi) (200 ppm), and troglitazone (Tro) (1,000 ppm) were investigated on the induction of the placental form of rat glutathione S-transferase (rGST P) positive foci, a precancerous lesion of the liver, and liver cancer formation using a diethylnitrosamine-induced liver cancer model in Wistar rats, and dose dependency of a PPARgamma ligand was also examined. RESULTS: PPARgamma ligands reduced the formation of rGST P-positive foci by diethylnitrosamine and induction of liver cancers was also markedly suppressed by a continuous feeding of Pio at 200 ppm. CONCLUSION: PPARgamma ligands are potential chemopreventive agents for liver carcinogenesis.

Stercoral colonic diverticulum perforation with jejunal diverticulitis mimicking upper gastrointestinal perforation.

Stercoral perforation of the colon is an unusual pathological condition with fewer than 150 cases reported in the literature to date. We present a case of stercoral colonic perforation mimicking upper gastrointestinal perforation, which was diagnosed by computed tomography preoperatively. However, at laparotomy, stercoral colonic diverticulum perforation with jejunal diverticulitis became the most appropriate diagnosis.