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Peritoneal dissemination is one of the most terrible types of colorectal cancer progression. Focal adhesion kinase (FAK) plays a crucial role in the biological processes of cancer, such as cell attachment, migration, proliferation and survival, all of which are essential for the progression of peritoneal dissemination. Since we and other groups have reported that the inhibition of FAK activity exhibited a potent anticancer effect in several cancer models, we hypothesized that TAE226, a novel ATP-competitive tyrosine kinase inhibitor designed to target FAK, can prevent the occurrence and progression of peritoneal dissemination. In vitro, TAE226 greatly inhibited the proliferation and migration of HCT116 colon cancer cells, while their adhesion on the matrix surface was minimally inhibited when FAK activity and expression was suppressed by TAE226 and siRNA. In vivo, when HCT116 cells were intraperitoneally inoculated in mice, the cells could attach to the peritoneum and begin to grow within 24 h regardless of the pretreatment of cells with TAE226 or FAK-siRNA, suggesting that FAK is not essential, at least for the initial integrin-matrix contact. Interestingly, the treatment of mice before and after inoculation significantly suppressed cell attachment to the peritoneum. Furthermore, oral administration of TAE226 greatly reduced the size of disseminated tumors and prolonged survival in tumor-bearing mice. Taken together, a possible strategy for inhibiting peritoneal dissemination by targeting FAK with TAE226 appears to be applicable through anti-proliferative and anti-invasion/anti-migration mechanisms.

Midkine (MDK) is a heparin-binding growth factor that is highly expressed in many malignant tumors, including lung cancers. MDK activates the PI3K pathway and induces anti-apoptotic activity, in turn enhancing the survival of tumors. Therefore, the inhibition of MDK is considered a potential strategy for cancer therapy. In the present study, we demonstrate a novel small molecule compound (iMDK) that targets MDK. iMDK inhibited the cell growth of MDK-positive H441 lung adenocarcinoma cells that harbor an oncogenic KRAS mutation and H520 squamous cell lung cancer cells, both of which are types of untreatable lung cancer. However, iMDK did not reduce the cell viability of MDK-negative A549 lung adenocarcinoma cells or normal human lung fibroblast (NHLF) cells indicating its specificity. iMDK suppressed the endogenous expression of MDK but not that of other growth factors such as PTN or VEGF. iMDK suppressed the growth of H441 cells by inhibiting the PI3K pathway and inducing apoptosis. Systemic administration of iMDK significantly inhibited tumor growth in a xenograft mouse model in vivo. Inhibition of MDK with iMDK provides a potential therapeutic approach for the treatment of lung cancers that are driven by MDK.

To assess the effects of a novel type 1 insulin-like growth factor receptor (IGF-1R) inhibitor, NVP-AEW541, on cell proliferation and signal transduction of esophageal cancer.Cell proliferation assay and western blot were conducted to assess the antitumor effects of NVP-AEW541. Genetic modification of RAS by expression vector was applied for overexpression of mutant RAS.More than 2 μmol/l of NVP-AEW541 was required to effectively inhibit the proliferation of esophageal cancer. NVP-AEW541 potently blocked the activation of IGF-1R and protein kinase B (PKB, also known as AKT), but not of mitogen-activated protein kinase kinase (MEK) and extracellular-signal-regulated kinases (ERK). Active RAS was not reduced by NVP-AEW541 in esophageal cancer cells TE-1, suggesting that insensitivity of esophageal cancer to NVP-AEW541 is due to the maintained RAS-MAPK activity, which did not arise from RAS mutation. Moreover, the transduction of mutant RAS reduced the sensitivity of TE-1 cells to NVP-AEW541.Stimulation of RAS-MAPK pathway is associated with resistance to NVP-AEW541 in esophageal cancer. Combining NVP-AEW541 with inhibitors/antibodies against RAS-MAPK signaling molecules might be more effective for use against esophageal cancer.

Heat shock protein 90 (HSP90), a molecular chaperone, has provoked great interest as a promising molecular target for cancer treatment, due to its involvement in regulating the conformation, stability and functions of key oncogenic proteins. At present, a variety of chemical compounds targeting HSP90 have been developed and have shown convincing anti-neoplastic activity in various preclinical tumor models. The aim of our study was to evaluate the antitumor effects of a novel HSP90 inhibitor, NVP-AUY922, in esophageal squamous cancer cells (ESCC). Four ESCC cell lines (TE-1, TE-4, TE-8, TE-10) were examined. NVP-AUY922 potently inhibited the proliferation of ESCC, particularly in PTEN-null TE-4 cells with a 2-3 times lower IC50 than the other three cell lines. Western blot analysis showed that PTEN-null TE-4 cells exhibited higher AKT and ERK activity, which contribute to cell proliferation and survival. NVP-AUY922 significantly suppressed the activity of AKT and ERK in TE-4 but not in PTEN-proficient TE-10 cells. Genetic modification experiments demonstrated that the sensitivity to NVP-AUY922 was decreased by exogenous transduction of PTEN in TE-4 and increased by silencing PTEN expression in intact PTEN-expressing TE-10, suggesting that the expression of PTEN may be associated with cell sensitivity in HSP90 inhibition. Furthermore, the enhanced activity of AKT in PTEN-silenced TE-10 was more easily suppressed by NVP-AUY922. Collectively, NVP-AUY922 exhibits a strong antiproliferative effect, revealing its potential as a novel therapeutic alternative to current ESCC treatment. The effect may be improved further by impeding PTEN expression.

Autophagy is a cellular lysosomal degradation pathway involved in proteins and organelles recycling for promoting cell survival, development and homeostasis. It is a multistep process and genetic studies have identified many proteins that participate in autophagosome formation and fusion with lysosomes, and various signaling factors that associate with the regulation of autophagy. In general, autophagy acts as a cell protector and its dysfunction is correlated with diverse pathologies, such as neurodegeneration, liver, heart and muscle diseases, cancer, inflammation and ageing. However, its role in cell death increases the complexity of the autophagic degradation system. A broad understanding of autophagy, ranging from detailed processes, including induction, formation and degradation, to function in physiology and pathology, revealed by accumulating studies, may be helpful for formulating therapeutic strategies for autophagy-associated human diseases.

We cloned the cDNA and genomic DNA encoding for Izumo1 of cashmere goat (Capra hircus) and sheep (Ovis aries). Analysis of 4.6 kb Izumo1 genomic sequences in sheep and goat revealed a canonical open reading frame (ORF) of 963 bp spliced by eight exons. Sheep and goat Izumo1 genes share >99% identity at both DNA and protein levels and are also highly homologous to the orthologues in cattle, mouse, rat and human. Extensive cloning and analysis of Izumo1 cDNA revealed three (del 69, del 182 and del 217) and two (del 69 and ins 30) alternative splicing isoforms in goat and sheep, respectively. All of the isoforms are derived from splicing at typical GT-AG sites leading to partial or complete truncation of the immunoglobulin (Ig)-like domain. Bioinformatics analysis showed that caprine and ovine Izumo1 proteins share similar structure with their murine orthologue. There are a signal peptide at the N-terminus (1–22 aa), a transmembrane domain at the C-terminus (302–319 aa), and an extracellular Ig-like region in the middle (161–252 aa) with a putative N-linked glycosylation site (N205-N-S). Alignment of Izumo1 protein sequences among 15 mammalian species displayed several highly conserved regions, including LDC and YRC motifs with cysteine residues for potential disulfide bridge formation, CPNKCG motif upstream of the Ig-like domain, GLTDYSFYRVW motif upstream of the putative N-linked glycosylation site, and a number of scattered cysteine residues. These distinctive features are very informative to pinpoint the important gene motifs and functions. The C-terminal regions, however, are more variable across species. Izumo1 cDNA sequences of goat, sheep, and cow were found to be largely homologous, and the molecular phylogenetic analysis is consistent with their morphological taxonomy. This implies the Izumo1 gene evolves from the same ancestor, and the mechanism of sperm–egg fusion in mammals may be under the same principle in which Izumo1 plays an important role.

Focal adhesion kinase (FAK) is a 125-kDa non-receptor protein tyrosine. Growth factors or the clustering of integrins facilitate the rapid phosphorylation of FAK at Tyr-397 and this in turn recruits Src-family protein tyrosine kinases, resulting in the phosphorylation of Tyr-576 and Tyr-577 in the FAK activation loop and full catalytic FAK activation. FAK plays a critical role in the biological processes of normal and cancer cells including the gastrointestinal tract. FAK also plays an important role in the restitution, cell survival and apoptosis and carcinogenesis of the gastrointestinal tract. FAK is over-expressed in cancer cells and its over-expression and elevated activities are associated with motility and invasion of cancer cells. FAK has been proposed as a potential target in cancer therapy. Small molecule inhibitors effectively inhibit the kinase activity of FAK and show a potent inhibitory effect for the proliferation and migration of tumor cells, indicating a high potential for application in cancer therapy.