Prostate cancer (PCa) is a leading cause of mortality and morbidity in men worldwide, and emerging evidence suggests that the CD44(high) prostate tumor-initiating cells (TICs) are associated with its poor prognosis. Although microRNAs are frequently dysregulated in human cancers, the influence of microRNAs on PCa malignancy and whether targeting TIC-associated microRNAs inhibit PCa progression remain unclear. In this study, we found that miR-320 is significantly downregulated in PCa. Overexpression of miR-320 in PCa cells decreases PCa tumorigenesis in vitro and in vivo. Global gene expression profiling of miR-320-overexpressing PCa cells reveals that downstream target genes of Wnt/β-catenin pathway and cancer stem cell markers are significantly decreased. MicroRNA-320 inhibits β-catenin expression by targeting the 3'-untranslated region of β-catenin mRNA. The reduction of miR-320 associated with increased β-catenin was also found in CD44(high) subpopulation of prostate cancer cells and clinical PCa specimens. Interestingly, knockdown of miR-320 significantly increases the cancer stem-like properties, such as tumorsphere formation, chemoresistance and tumorigenic abilities, although enriching the population of stem-like TICs among PCa cells. Furthermore, increased miR-320 expression in prostate stem-like TICs significantly suppresses stem cell-like properties of PCa cells. These results support that miR-320 is a key negative regulator in prostate TICs, and suggest developing miR-320 as a novel therapeutic agent may offer benefits for PCa treatment.

Tumor angiogenesis is a critical process during cancer progression that modulates tumor growth and metastasis. Here, we identified an anti-angiogenic microRNA, miR-320, which is decreased in oral squamous cell carcinoma (OSCC) cell lines and tumor tissues from OSCC patients, down-regulated in blood vessels and inversely correlated with vascularity in OSCC tissues. Neuropilin 1 (NRP1), an important regulator of angiogenesis, was found to be a target of miR-320. The 3'-untranslated region of NRP1 mRNA contains multiple miR-320 binding sites, and its expression was regulated by miR-320. By administering either miR-320 precursor or antagonist, we found that miR-320 suppressed the migration, adhesion and tube formation of vascular endothelial cells. Knockdown of NRP1 abolished antagomiR-320-induced cell migration. Additionally, miR-320 expression was regulated by hypoxia in growth factor-deficient conditions by the hypoxia-inducible factor 1-alpha. Furthermore, lentivirus carrying the miR-320 precursor suppressed the tumorigenicity of OSCC cells and tumor angiogenesis in vivo. Taken together, these data show that miR-320 regulates the function of vascular endothelial cells by targeting NRP1 and has the potential to be developed as an anti-angiogenic or anti-cancer drug.

Myofibroblasts have a key role in wound healing by secreting growth factors and chemoattractants to create new substrates and proteins in the extracellular matrix. We have found that galectin-1, a β-galactose-binding lectin involved in many physiological functions, induces myofibroblast activation; however, the mechanism remains unclear. Here, we reveal that galectin-1-null (Lgals1(-/-)) mice exhibited a delayed cutaneous wound healing response. Galectin-1 induced myofibroblast activation, migration, and proliferation by triggering intracellular reactive oxygen species (ROS) production. A ROS-producing protein, NADPH oxidase 4 (NOX4), was upregulated by galectin-1 through the neuropilin-1/Smad3 signaling pathway in myofibroblasts. Subcutaneous injection of galectin-1 into wound areas accelerated the healing of general and pathological (streptozotocin-induced diabetes mellitus) wounds and decreased the mortality of diabetic mice with skin wounds. These findings indicate that galectin-1 is a key regulator of wound repair that has therapeutic potential for pathological or imperfect wound healing.

a-Catulin is an oncoprotein that helps sustain proliferation by preventing cellular senescence. Here, we report that a-catulin also drives malignant invasion and metastasis. a-Catulin was upregulated in highly invasive nonsmall cell lung cancer (NSCLC) cell lines, where its ectopic expression or short-hairpin RNA-mediated attenuation enhanced or limited invasion or metastasis, respectively. a-Catulin interacted with integrin-linked kinase (ILK), a serine/threonine protein kinase implicated in cancer cell proliferation, antiapoptosis, invasion, and angiogenesis. Attenuation of ILK or a-catulin reciprocally blocked cell migration and invasion induced by the other protein. Mechanistic investigations revealed that a-catulin activated Akt-NF-kB signaling downstream of ILK, which in turn led to increased expression of fibronectin and integrin avb3. Pharmacologic or antibodymediated blockade of NF-kB or avb3 was sufficient to inhibit a-catulin-induced cell migration and invasion. Clinically, high levels of expression of a-catulin and ILK were associated with poor overall survival in patients with NSCLC. Taken together, our study shows that a-catulin plays a critical role in cancer metastasis by activating the ILK-mediated Akt-NF-kB-avb3 signaling axis. Cancer Res; 73(1); 428-38. Ó2012 AACR.

Peptide-29 selected from biopanning may have clinical potential for HNSCC.

Most oral squamous cell carcinoma (OSCC) tumors arise from oral premalignant lesions. Oral submucous fibrosis (OSF), usually occurring in male chewers of betel quid, is a premalignant stromal disease characterized by a high malignant transformation rate and high prevalence. Although a relationship between the inhabited microbiome and carcinogenesis has been proposed, no detailed information regarding the oral microbiome of patients with OSF exists; the changes of the salivary microbiome during cancer formation remain unclear. This study compared the salivary microbiomes of male patients with OSCC and a predisposing OSF background (OSCC-OSF group) and those with OSF only (OSF group). The results of high-throughput sequencing of the bacterial 16S rRNA gene indicated that OSF-related carcinogenesis and smoking status significantly contributed to phylogenetic composition variations in the salivary microbiome, leading to considerable reductions in species richness and phylogenetic diversity. The microbiome profile of OSF-related malignancy was associated with increased microbial stochastic fluctuation, which dominated the salivary microbiome assembly and caused species co-occurrence network collapse. Artificial intelligence selection algorithms consistently identified 5 key species in the OSCC-OSF group: Porphyromonas catoniae, Prevotella multisaccharivorax, Prevotella sp. HMT-300, Mitsuokella sp. HMT-131, and Treponema sp. HMT-927. Robust accuracy in predicting oral carcinogenesis was obtained with our exploratory and validation data sets. In functional analysis, the microbiome of the OSCC-OSF group had greater potential for S-adenosyl-l-methionine and norspermidine synthesis but lower potential for l-ornithine and pyrimidine deoxyribonucleotide synthesis and formaldehyde metabolism. These findings indicated that the salivary microbiome plays important roles in modulating microbial metabolites during oral carcinogenesis. In conclusion, our results provided new insights into salivary microbiome alterations during the malignant transformation of OSF.

Ovarian clear cell carcinoma (OCCC) is an aggressive neoplasm with a high recurrence rate that frequently develops resistance to platinum-based chemotherapy. There are few prognostic biomarkers or targeted therapies exist for patients with OCCC. Here, we identified that FXYD2, the modulating subunit of Na+/K+-ATPases, was highly and specifically expressed in clinical OCCC tissues. The expression levels of FXYD2 were significantly higher in advanced-stage of OCCC and positively correlated with patients' prognoses. Silencing of FXYD2 expression in OCCC cells inhibited Na+/K+-ATPase enzyme activity and suppressed tumor growth via induction of autophagy-mediated cell death. We found that high FXYD2 expression in OCCC was transcriptionally regulated by the transcriptional factor HNF1B. Furthermore, up-regulation of FXYD2 expression significantly increased the sensitivity of OCCC cells to cardiac glycosides, the Na+/K+-ATPase inhibitors. Two cardiac glycosides, digoxin and digitoxin, had a great therapeutic efficacy in OCCC cells in vitro and in vivo. Taken together, our results demonstrate that FXYD2 is functionally upregulated in OCCC and may serve as a promising prognostic biomarker and therapeutic target of cardiac glycosides in OCCC.

Two new variants of short disintegrins were purified from the venom of Echis carinatus leakeyi and named echistatin beta and gamma. These proteins were found to be about 85% similar in amino acid sequence to echistatin alpha which has been well studied. The disulphide pattern of echistatin gamma appeared to be identical with that of echistatin alpha. They all contain the adhesive recognition sequence Arg-Gly-Asp (RGD) but inhibit the aggregation of platelets from human and other mammals with different potencies. Echistatin beta and alpha are far more effective on platelets from humans and guinea pigs than those from rabbits and rats whereas echistatin gamma is less discriminating of the platelets of the species tested. This species-dependent platelet sensitivity to echistatin beta and gamma could be attributed to the variations in residues 15, 21, 22 and 27, which are close to or within the RGD loop, rather than to the C-terminal variations after residue 46. Taking advantage of the presence of methionine residues flanking both sides of the ARGDDM motif in echistatin gamma, we deleted this hexapeptide by CNBr cleavage to produce des-(23-28)-echistatin gamma. The modified protein showed c.d. and fluorescent spectra grossly similar to the intact echistatin but its antiplatelet potency decreased more than 200-fold. We thus propose that a favourable conformation of the RGD region is responsible mainly for the high-affinity binding of echistatin to the platelet glycoprotein IIb-IIIa as shown previously for the binding of medium-size disintegrin.