Clinical implications of HER-2/neu overexpression and proteolytic activity imbalance in breast cancer

The aggressive biological behavior of invasive and metastatic cancer is considered to be the most insidious and life-threatening aspect for breast cancer patients. It is mostly the result of changes in many molecular characteristics of tumor cells, including alterations in gene expression and the balance of proteolytic activity. The objective of this study was to determine the level of MMP-2, its natural inhibitor TIMP-2, their ratio and HER-2/neu as diagnostic and prognostic factors. Markers were analyzed in 240 tissue samples categorized into 96 benign breast disease and 144 breast cancer patients. Enzyme linked immunosorbent assay procedure was used to evaluate the level of MMP-2 and TIMP-2 in the cell lysate, HER-2/neu in the membrane fraction, and steroid hormone receptors (ER and PgR) in the cytosol fraction. Breast cancer patients were followed-up for three years. Receiver operating characteristic curves were used to determine the cutoff points for the investigated factors. Positive values for all investigated factors were significantly increased in breast cancer patients compared to benign ones. Mean levels for all investigated factors were significantly correlated with lymph node and hormone receptor status, while MMP-2 and TIMP-2 were correlated with tumor grade (P < 0.05). In Univariate analysis, positive MMP-2, MMP-2/TIMP-2, HER-2/neu overexpression, higher tumor grade, late clinical stages and positive lymph nodes status were significantly associated with relapse. By multivariate analysis, all aforementioned factors apart from tumor grade were independent variables. Thus, the investigated markers are constructive for biologic aggressiveness of breast cancer and MMP-2/TIMP-2 ratio might be a new significant marker in early diagnosis and estimate prognosis in breast cancer.     

Aberrant Expression of Some Circulating miRNAs in Childhood Acute Lymphoblastic Leukemia

Acute lymphoblastic leukemia (ALL) is a heterogeneous cancer commonly affecting children due to dysregulation of miRNA expression. In the current study, authors investigated the expression profile for miRNA-125b-1 and miRNA-203 among childhood ALL. Blood samples were collected from newly diagnosed childhood ALL and healthy control children. The expression profile for candidate miRNAs was detected using quantitative RT-PCR analysis. Statistical analysis were performed using receiver operating characteristic curve (ROC) to examine the diagnostic efficacy of the two miRNA and their levels among ALL clinicopathological factors and phenotypes. The median expression level for miRNA-125b-1 was significantly high in childhood ALL; while miRNA-203 level was significantly low in childhood ALL as compared to control ones. MiRNA-125-1 reported significant increase in T-ALL as compared to other ALL phenotypes. Median miRNA-203 level was high in T-ALL followed by pre-B-ALL although no significant difference was reported. Clinicopathological factors did not emphasize significance with either detected miRNAs. Using ROC curve the diagnostic efficacy was significant with an area under the curve 0.858 for miRNA-125b-1 (83.72, 100%) and 0.878 for miRNA-203 (97.67, 86.96%). The combination of the two key miRNAs revealed absolute sensitivity (100%). MiRNA-125b-1 and miRNA-203 can be useful molecular markers for diagnosis of ALL. Further studies with large cohort are warranted to validate these results.     

miRNA-155 and miRNA-181a as prognostic biomarkers for pediatric acute lymphoblastic leukemia

Mortality rates of acute lymphoblastic leukemia (ALL) have improved over the past 20 years; however, a significant portion of deaths stems from the lack of prognostic biomarkers, which can direct therapy and overcome drug resistance. microRNA-155a (miRNA-155a) and miRNA-181a are two single-stranded miRNAs involved in the pathogenesis of many types of leukemia and lymphoma and is linked to drug resistance. We investigated their expression levels in 55 patients, 45 diagnosed with ALL and 10 as a control group. We found that miRNA-155a and miRNA-181a were significantly upregulated in the ALL group with both being linked to high levels of minimal residual disease and poor prognosis. miRNA-155a cutoff value was significant in discriminating between high- and low-risk ALL patients as well as between ALL patients and healthy controls, miRNA-181a cutoff value, however, was not significant. Both markers levels were significantly downregulated after therapy. We conclude that miR-155 is correlated with poor prognosis in ALL, whereas we couldn’t link miRNA-181a to the prognosis in ALL. Moreover, the marked decrease in their expression after therapy could reflect their impact on disease outcome.     

Clinical significance of blood-based miRNAs as diagnostic and prognostic nucleic acid markers in breast cancer: Comparative to conventional tumor markers

microRNAs (miRNAs) are implicated in carcinogenesis and their expression in biological fluids offer great potential as nucleic acid markers for cancer detection and progression. Authors investigated the expression level of miRNAs (miRNA-21, miRNA-126, and miRNA-155) to evaluate their role as diagnostic and prognostic markers for breast cancer compared with other commonly used protein-based markers (CEA and CA15-3). Serum samples from patients with breast cancer (n = 96), patients with benign breast lesion (n = 47), and healthy individuals (n = 39) were enrolled for detection of miRNA expression levels and protein-based tumor markers using fluorescent real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Correlation among investigated markers with clinicopathological factors and clinical outcomes were determined. Expression of miRNA-21 and miRNA-155 revealed significant increases in patients with breast cancer compared with both benign and control groups, the same result was reported for tumor markers; on the other hand, miRNA-126 was significantly decreased in breast cancer group as compared with the other two groups. miRNA frequencies were significantly related to clinical staging and histological grading as compared with tumor markers. Patients with breast cancer with increased miRNA-21 and miRNA-155 and decreased miRNA-126 expressions had significantly worse disease-free survival, while only miRNA-21 and miRNA-126 showed poor OS (P< 0.005). In conclusion, investigated miRNAs were superior over tumor markers for the early stage of breast cancer especially those with high-risk factor and their assessment in blood facilitates their role as a potential prognostic molecular marker.     

Production of PHB by a Bacillus megaterium strain using sugarcane molasses and corn steep liquor as sole carbon and nitrogen sources

Poly(hydroxybutyric acid) (PHB) and other biodegradable polyesters are promising candidates for the development of environment-friendly, totally biodegradable plastics. The use of cane molasses and corn steep liquor, two of the cheapest substrates available in Egypt, may help to reduce the cost of producing such biopolyesters. In this work, the effect of different carbon sources was studied. Maximum production of PHB was obtained with cane molasses and glucose as sole carbon sources (40.8, 39.9 per mg cell dry matter, respectively). The best growth was obtained with 3% molasses, while maximum yield of PHB (46.2% per mg cell dry matter) was obtained with 2% molasses. Corn steep liquor was the best nitrogen source for PHB synthesis (32.7 mg per cell dry matter), on the other hand, best growth was observed when ammonium chloride, ammonium sulphate, ammonium oxalate or ammonium phosphate were used as nitrogen sources.     

Emerging role of p53, bcl-2 and telomerase activity in Egyptian breast cancer patients

Apoptotic cell death represents an important mechanism for the precise regulation of cell numbers, and a defense mechanism against tumor cells. Both bcl-2 and mutant p53 gene products have been involved in apoptotic pathways. On the other hand, cell proliferation capacity and tumorgenesis have been controlled by telomerase. The purpose of our study is to assess the prognostic significance of additional markers implicated in apoptosis and tumorgenesis. Fifty-one fresh tissue samples of primary breast carcinoma and 26 tissue samples of benign breast lesions were included in this study. Expression of bcl-2 in cell lysates and mutant p53 protein in nuclear fraction were measured by Oncogene Science EIA procedures. Telomerase activity was analyzed using the Telomerase-PCR-ELISA based on the TRAP (telomerase repeat amplification protocol) method. On the same specimens, steroid hormone receptors (ER and PgR) were measured in cytosol fraction using Abbott EIA assays. In addition, information regarding surgical-pathological features of the tumor was obtained. Univariate and Multivariate analysis was done to identify variables predictive of poor prognosis. Significant expression of bcl-2, mutant p53 proteins and relative telomerase activity were observed in malignant cases when compared to benign ones. Univariate analysis revealed significant association in the level of both mutant p53 and relative telomerase activity with tumor size and disease recurrence. Moreover, telomerase activity was significantly expressed in late stages than early ones. Multivariate analysis revealed that bcl-2, mutant p53, telomerase activity, PgR and age were independent prognostic factors. Among a panel of molecular genetic factors investigated, mutant p53 and relative telomerase activity were strongly associated with disease recurrence; hence they exert a significant prognostic role in breast cancer.     

Association of nonalcoholic fatty liver disease with a single nucleotide polymorphism on the gene encoding leptin receptor

Leptin (Lep), a 16-kDa polypeptide hormone, exerts its action through the leptin receptor (LepRb), a member of the class I cytokine receptor family. Both leptin and LepRb probably have been implicated in pathogenesis of nonalcoholic fatty liver disease (NAFLD). This study was designed to assess the role of soluble leptin and LepRb in NAFLD and to investigate whether leptin receptor gene (LepR) single nucleotide polymorphism (SNP; ID rs6700896) influences NAFLD complicated with or without type 2 diabetes mellitus (T2DM). Blood samples from 90 obese NAFLD cases and 30 lean controls of matched age and sex were recruited in the study. Among the NAFLD patients, 32 were T2DM. Plasma leptin and LepRb levels were measured by enzyme linked immunoassay (ELISA). Lipids profile, glucose metabolic parameters, and insulin concentration were measured for all participants. Body mass index (BMI) and insulin resistance (IR) were calculated as well. Genotyping was done using SNP (rs6700986) for LepR gene. Significant difference was reported between NAFLD with or without T2DM and control regarding biochemical markers and LepR genotype and allele frequencies. Mutant homozygous and heterozygous LepR genotype and mutant allele were significantly higher in mild-severe steatosis and in NAFLD with T2DM when compared with mild steatosis and those without T2DM. Frequencies of mutant LepR polymorphism were significantly associated with IR increment. Elevated leptin level seems to be a feature of steatosis, and it appears to increase as hepatocyte steatosis develops. Moreover, polymorphism of LepR gene contributes to the onset of NAFLD by regulating lipid metabolism and affecting insulin sensitivity.