The extracellular domain of epithelial cell adhesion molecule (EpCAM) enhances multipotency of mesenchymal stem cells through EGFR-LIN28-LET7 signaling.

Mesenchymal stem cells (MSCs) are widely considered to be an attractive cell source for regenerative therapies, but maintaining multipotency and self-renewal in cultured MSCs is especially challenging. Hence, the development and mechanistic description of strategies that help promote multipotency in MSCs will be vital to future clinical use. Here, using an array of techniques and approaches, including cell biology, RT-quantitative PCR, immunoblotting, immunofluorescence, flow cytometry, and ChIP assays, we show that the extracellular domain of epithelial cell adhesion molecule (EpCAM) (EpEX) significantly increases the levels of pluripotency factors through a signaling cascade that includes epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT3), and Lin-28 homolog A (LIN28) and enhances the proliferation of human bone marrow MSCs. Moreover, we found that EpEX-induced LIN28 expression reduces the expression of the microRNA LET7 and up-regulates that of the transcription factor high-mobility group AT-hook 2 (HMGA2), which activates the transcription of pluripotency factors. Surprisingly, we found that EpEX treatment also enhances osteogenesis of MSCs under differentiation conditions, as evidenced by increases in osteogenic markers, including Runt-related transcription factor 2 (RUNX2). Taken together, our results indicate that EpEX stimulates EGFR signaling and thereby context-dependently controls MSC states and activities, promoting cell proliferation and multipotency under maintenance conditions and osteogenesis under differentiation conditions.

Targeted drug delivery systems mediated by a novel Peptide in breast cancer therapy and imaging.

Targeted delivery of drugs to tumors represents a significant advance in cancer diagnosis and therapy. Therefore, development of novel tumor-specific ligands or pharmaceutical nanocarriers is highly desirable. In this study, we utilized phage display to identify a new targeting peptide, SP90, which specifically binds to breast cancer cells, and recognizes tumor tissues from breast cancer patients. We used confocal and electron microscopy to reveal that conjugation of SP90 with liposomes enables efficient delivery of drugs into cancer cells through endocytosis. Furthermore, in vivo fluorescent imaging demonstrated that SP90-conjugated quantum dots possess tumor-targeting properties. In tumor xenograft and orthotopic models, SP90-conjugated liposomal doxorubicin was found to improve the therapeutic index of the chemotherapeutic drug by selectively increasing its accumulation in tumors. We conclude that the targeting peptide SP90 has significant potential in improving the clinical benefits of chemotherapy in the treatment and the diagnosis of breast cancer.

Plectranthus amboinicus and Centella asiatica Cream for the Treatment of Diabetic Foot Ulcers.

Effects of a topical cream containing P. amboinicus (Lour.) Spreng. (Lamiaceae) and C. asiatica (L.) Urban (Umbelliferae) were evaluated and compared to effects of hydrocolloid fiber wound dressing for diabetic foot ulcers. A single-center, randomized, controlled, open-label study was conducted. Twenty-four type 1 or type 2 diabetes patients aged 20 years or older with Wagner grade 3 foot ulcers postsurgical debridement were enrolled between October 2008 and December 2009. Twelve randomly assigned patients were treated with WH-1 cream containing P. amboinicus and C. asiatica twice daily for two weeks. Another 12 patients were treated with hydrocolloid fiber dressings changed at 7 days or when clinically indicated. Wound condition and safety were assessed at days 7 and 14 and results were compared between groups. No statistically significant differences were seen in percent changes in wound size at 7- and 14-day assessments of WH-1 cream and hydrocolloid dressing groups. A slightly higher proportion of patients in the WH-1 cream group (10 of 12; 90.9%) showed Wagner grade improvement compared to the hydrocolloid fiber dressing group but without statistical significance. For treating diabetic foot ulcers, P. amboinicus and C. asiatica cream is a safe alternative to hydrocolloid fiber dressing without significant difference in effectiveness.

Nucleolin antisense oligodeoxynucleotides induce apoptosis and may be used as a potential drug for nasopharyngeal carcinoma therapy.

Nucleolin (C23, NCL) mRNA was up-regulated in nasopharyngeal carcinoma (NPC) cells compared to that of normal nasomucosal (NNM) cells using a cDNA microarray approach. The level of nucleolin protein was also up-regulated in 13 NPC cell lines, 30 biopsy specimens and nine other cancer cell lines compared to five NNM cells or normal stromal cells, which were analyzed using immunoblotting or immunohistochemistry. We transfected nucleolin antisense oligodeoxynucleotides (phosphorothioate-modified oligodeoxynucleotides; S-ODNs) into NPC-TW01 cells to knockdown nucleolin expression to evaluate the function of nucleolin in cancer cells. Nucleolin knockdown induced NPC cells but not NNM cells to undergo apoptosis. Furthermore, treatment of NPC-TW01 xenograft tumors with nucleolin antisense oligodeoxynucleotides suppressed the growth of xenograft tumors without obvious side effects. Therefore, we suggest that nucleolin may be a potential cancer therapeutic target and that nucleolin antisense oligodeoxynucleotides may be used as a potential drug for therapy in NPC.

MicroRNA-1 induces apoptosis by targeting prothymosin alpha in nasopharyngeal carcinoma cells.

BACKGROUND: MiR-1 (microRNA-1) has been used as a positive control in some microRNA experiments. We found that miR-1 transfection of nasopharyngeal carcinoma cells reveals a typical apoptotic process as shown by time-lapse microscopy so we investigated the mechanisms of miR-1 inducing apoptosis. METHODS: To confirm that miR-1 induces apoptosis, we used Annexin V and TUNEL staining and caspase assay. To determine that miR-1 directly targets genes that involve in apoptosis, we analyzed microRNA and pathway databases, and cDNA expression microarrays from miR-1 transfected cells. To demonstrate candidate miR-1 targeted genes, we used qRT-PCR analysis and luciferase reporter vector assays. To assess the miR-1 target gene PTMA (prothymosin alpha, ProTalpha) involves in apoptosis, we used PTMA siRNA to knock down PTMA. RESULTS: Annexin V and TUNEL staining and caspase assay confirm that miR-1 induces nasopharyngeal carcinoma cell apoptosis. MiR-1 transfection of HeLa, Cal-27, KYSE30 and NPC-TW06 cell lines which express low levels of endogenous miR-1 also induces apoptosis. However, miR-1 transfection of cell lines such as SW620, HepG2, HEK-293T, SAS and PC-13 which express high levels of endogenous miR-1 does not result in apoptosis. MiR-1 directly targets PTMA gene. PTMA siRNA and miR-1 accelerate the apoptotic process in cells treated with apoptosis inducers. CONCLUSIONS: The exogenous expression of miR-1 induces apoptosis in a number of cell lines. This is a model of microRNA-induced cell apoptosis. The PTMA is one of miR-1 target genes which involve in miR-1 inducing apoptosis. The apoptotic inducers including actinomycin D, camptothecin and etoposide are also the chemotherapeutic drugs in clinical cancer therapy and PTMA siRNA can accelerate apoptotic progression in cells treated with those apoptosis inducers. Therefore PTMA siRNA may have potential applications as an adjuvant in cancer chemotherapy.

IGFBP-6 plays a role as an oncosuppressor gene in NPC pathogenesis through regulating EGR-1 expression.

Nasopharyngeal carcinoma (NPC) is prevalent in south-eastern Asia, particularly southern China, Singapore and Taiwan. The aim of this study was to identify the pivotal genes that may be altered during NPC progression. Using cDNA microarray analysis, we compared the expression of 18 genes between NPC and normal nasomucosal cells. qRT-PCR analysis found the expression of IBFBP-6 in NPC cell lines and immunolocalization of IGFBP-6 in NPC to be very weak. To explore the effects of IGFBP-6 on NPC tumour growth, we constructed inducible plasmids containing full-length IGFBP-6 cDNA (pBIG2i-IGFBP-6) and established pBIG2i-IGFBP-6-transfected NPC stable cell lines (NPC-TW01-pBIG2i-IGFBP-6). We then performed functional analysis of the IGFBP-6 in cell lines in vitro and in vivo. Over-expression of IGFBP-6 significantly suppressed the proliferation, invasion and metastatic activity of NPC cells and increased their apoptosis. We found the EGR-1, caspase-1 and TSP-1 genes to be markedly up-regulated when NPC-pBIG2i-IGFBP-6 was treated with doxycycline. Knocking down EGR-1 with EGR-1 siRNA resulted in a decrease in expression of caspase-1, TSP-1 and EGR-1 but not the expression of IGFBP-6. However, in knockdown cells the unchanged expression of IGFBP-6 did not inhibit the migration of NPC cells. Chromatin immunoprecipitation and luciferase reporter assay experiments showed that IGFBP-6 bound the EGR-1 promoter regions and activated EGR-1 promoter. We conclude that IGFBP-6 can regulate the progression of NPC by regulating the expression of EGR-1. These results suggest that IGFBP-6 could be used as a new target in NPC therapy.

NOLC1, an enhancer of nasopharyngeal carcinoma progression, is essential for TP53 to regulate MDM2 expression.

Nasopharyngeal carcinoma (NPC) is one of the most common cancers among Chinese living in South China, Singapore, and Taiwan. At present, its etiological factors are not well defined. To identify which genetic alterations might be involved in NPC pathogenesis, we identified genes that were differentially expressed in NPC cell lines and normal nasomucosal cells using subtractive hybridization and microarray analysis. Most NPC cell lines and biopsy specimens were found to have higher expression levels of the gene encoding nucleolar and coiled-body phosphoprotein 1 (NOLC1) as compared with normal cells. Severe combined immunodeficiency mice bearing NPC xenografts derived from NOLC1-short hairpin-RNA-transfected animals were found to have 82% lower levels of tumor growth than control mice as well as marked tumor cell apoptosis. Measuring the expression levels of genes related to cell growth, apoptosis, and angiogenesis, we found that the MDM2 gene was down-regulated in the transfectants. Both co-transfection and chromatin immunoprecipitation experiments showed that tumor protein 53-regulated expression of the MDM2 gene requires co-activation of NOLC1. These findings suggest that NOLC1 plays a role in the regulation of tumorigenesis of NPC and demonstrate that both NOLC1 and tumor protein 53 work together synergistically to activate the MDM2 promoter in NPC cells.

Factors affecting the mortality of necrotizing fasciitis involving the upper extremities.

PURPOSE: Necrotizing fasciitis involving the upper extremities is an uncommon, but potentially life-threatening infection. Surgical records were reviewed to identify its mortality risk factors. METHODS: A 10-year retrospective review was conducted of all patients with upper limb necrotizing fasciitis treated in a tertiary care hospital in northern Taiwan. The demographic data, physical and laboratory findings and salient information with respect to the treatment and clinical outcome were collected and analyzed. RESULTS: Fourteen patients were identified. The mean age of the all-male cohort was 60.2 years (range, 44-83 years). Five of the patients died, yielding a mortality rate of 35.7%. At the time of presentation, all 14 patients had pain and swelling, but fever occurred in only 7 patients. Associated chronic debilitating diseases, of which diabetes mellitus was the most common, were present in 9 individuals. Patients underwent an average of two surgical debridements. The initial presentation in a state of altered consciousness or respiratory distress was found to be a statistically significant factors for eventual mortality (P < 0.05). CONCLUSION: The results showed that necrotizing fasciitis of the upper extremity is associated with a high mortality rate. Early diagnosis and referral for aggressive surgical treatment before the development of systemic toxic signs are therefore considered to be essential for survival.

Bacteremic necrotizing fasciitis caused by Vibrio cholerae serogroup O56 in a patient with liver cirrhosis.

Bacteremic necrotizing fasciitis caused by non-O1 Vibrio cholerae has rarely been reported. We describe a case of necrotizing fasciitis of the bilateral lower extremities in a 68-year-old man with liver cirrhosis and diabetes mellitus. Cultures of blood and the debrided tissue all yielded V. cholerae serogroup non-O1 (O56). Despite extensive radical debridement and antibiotic treatment with ceftazidime and doxycycline, the patient died on the 12th hospital day due to multiple organ failure. The present case is the first report of necrotizing fasciitis and bacteremia caused by V. cholerae serogroup O56.