Impact of circ-0000221 in the Pathogenesis of Hepatocellular via Modulation of miR-661-PTPN11 mRNA Axis.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death in Egypt. A deep understanding of the molecular events occurring in HCC can facilitate the development of novel diagnostic and/or therapeutic approaches. In the present study, we describe a novel axis of hsa-circ-0000221-miR-661-PTPN11 mRNA proposed by in silico and in vitro analysis and its role in HCC pathogenesis. We observe a reduction in the expression levels of hsa-circ-0000221 and PTPN11 mRNA in HCC patients' sera tested compared with control subjects. The reduction occurs with a concomitant increase in the expression of miR-661. Furthermore, the introduction of exogenous hsa-circ-0000221 into Hep-G2 or SNU449 cell lines results in detectable decrease in cellular viability and an increase in apoptotic manifestations that is associated with G1 accumulation and CCDN1 overexpression. Altogether, these findings indicate the tumor-suppressive role of hsa-circ-0000221 in HCC, which acts through miR-661 inhibition, along with a subsequent PTPN11 mRNA increase, where PTPN11 is known to inhibit cell proliferation in many forms of cancer. Our study encourages further investigation of the role of circRNAs in cancer and their potential use as molecular biomarkers.

Molecular Characterization of Carbapenemase-Producing Klebsiella pneumoniae Isolated from Egyptian Pediatric Cancer Patients Including a Strain with a Rare Gene-Combination of ß-Lactamases.

PURPOSE: Healthcare-associated infections caused by multi-drug-resistant (MDR) pathogens are a global threat. We aim to assess the clonal relatedness among carbapenemase-producing Klebsiella pneumoniae (CPKP) strains infecting Egyptian pediatric cancer patients. MATERIALS AND METHODS: Identification and antimicrobial susceptibility testing of 149 Gram-negative isolates obtained from pediatric cancer patients were performed by VITEK 2. Genes encoding carbapenemases and extended-spectrum ß-lactamases were detected by PCR and verified by DNA sequencing of representative samples. The transferability of the plasmids harboring bla OXA-48, from representative clinical samples, was evaluated by performing a conjugation experiment followed by PCR and MIC shift determination. Clonal relationships among the bla OXA-48-harboring K. pneumoniae isolates were determined by enterobacterial repetitive intergenic consensus (ERIC)-PCR and pulsed-field gel electrophoresis (PFGE). RESULTS: Carbapenem resistance was observed in 59% of the isolates. The most prevalent species was K. pneumoniae (45.6%) and 57% of them were isolated from ICU. Fifty-nine % of the K. pneumoniae isolates were carbapenemase-producers and bla OXA-48 was detected in (58%) of them. One isolate co-harbored bla OXA-48, bla NDM-1, and bla IMP-1 genes for the first time in Egypt. PCR and meropenem MIC shift confirmed the success of the transferability of representative plasmids to E. coli K12. ERIC and PFGE identified 93% and 100% of the K. pneumoniae with a similarity coefficient ≥85%, respectively, including strains with indistinguishable patterns, suggesting possible clonal dissemination. CONCLUSION: Our findings underline the dissemination of diverse clones of MDR CPKP among Egyptian pediatric cancer patients. Hence, routine molecular characterizations followed by strict implementation of infection control measures are crucial to tackling this threat.

Inhibition of aldehyde dehydrogenase-1 and p-glycoprotein-mediated multidrug resistance by curcumin and vitamin D3 increases sensitivity to paclitaxel in breast cancer.

Treatment of breast cancer by paclitaxel (PAX) often encounters therapeutic failure most likely caused by innate/acquired resistance. Cancer stem cells (CSCs) and multidrug resistance complex (MDR-1 or P-glycoprotein) overexpression are main mechanisms implicated in chemoresistance. Increased aldehyde dehrogenase-1 (ALDH-1) was previously correlated with the stemness features of CSCs and hence is used as a marker for identification and CSCs targeting. The present study, therefore, aimed at investigating the effect of both curcumin (CUR) and vitamin D3 (D3) on MDR-1 and ALDH-1 expression and consequently the resistance to PAX both in vitro and in vivo. CUR was isolated from Turmeric rhizomes and identified using UPLC-ESI-MS/MS. For in vitro studies, the antiproliferative effect of PAX, CUR, 1,25(OH)2D3 (the active form of D3, also known as calcitriol) was determined, each alone and combined (PAX+CUR, PAX+1,25(OH)2D3, and PAX+CUR+1,25(OH)2D3) on MCF-7 breast cancer cells. Ehrlich ascites carcinoma solid tumor animal model was also used for in vivo studies. Combining CUR and/or 1,25(OH)2D3 to PAX showed synergistic cytotoxic interaction on MCF-7 cells. The apoptotic potential was also enhanced, as evidenced by a significant increase in caspase-7 and -9 as well as the pro-apoptotic Bax whereas a decrease in Bcl-2 levels was reported. Combining CUR and 1,25(OH)2D3 to PAX caused a downregulation in both MDR-1 and ALDH-1 gene expression in MCF-7 besides a decrease in their protein levels. In vivo, the triple therapy group (PAX+CUR+D3) showed the least tumor size. It also showed the lowest levels of MDR-1 and ALDH-1. PAX alone, however, showed increased levels of MDR-1 and ALDH-1 compared to control. Overall, the present study showed that PAX, as a monotherapy, demonstrated acquired resistance possibly by increasing MDR-1 expression and enriching CSCs population, as evidenced by increased ALDH-1. However, using CUR and D3 enhanced tumor response to PAX.

Clinical significance of immunophenotypic markers in pediatric T-cell acute lymphoblastic leukemia.

BACKGROUND: Cell-marker profiling has led to conflicting conclusions about its prognostic significance in T-ALL. AIM: To investigate the prevalence of the expression of CD34, CD10 and myeloid associated antigens (CD13/ CD33) in childhood T-ALL and to relate their presence to initial clinical and biologic features and early response to therapy. PATIENTS AND METHODS: This study included 67 consecutive patients with newly diagnosed T-ALL recruited from the Children's Cancer Hospital in Egypt during the time period from July 2007 to June 2008. Immunophenotypic markers and minimal residual disease (MRD) were studied by five-color flow cytometry. RESULTS: The frequency of CD34 was 34.9% , CD10 33.3% , while CD13/CD33 was 18.8%. No significant association was encountered between CD34, CD10 or myeloid antigen positivity and the presenting clinical features as age, sex, TLC and CNS leukemia. Only CD10(+) expression had significant association with initial CNS involvement (p=0.039). CD34 and CD13/CD33 expression was significantly associated with T-cell maturation stages (p<0.05). No relationship was observed for age, TLC, gender, NCI risk or CNS involvement with early response to therapy illustrated by BM as well as MRD day 15 and day 42. CD34(+), CD13/CD33(+) and early T-cell stage had high MRD levels on day 15 that was statistically highly significant (p<0.01), but CD10(+) had statistically significant lower MRD level on day 15 (p=0.049). However, only CD34 retained its significance at an MRD cut-off level of 0.01%. CONCLUSIONS: CD34, CD10, CD13/CD33 expression, as well as T-cell maturation stages, may have prognostic significance in pediatric T-ALL as they have a significant impact on early clearance of leukemic cells detected by MRD day 15.