A glycolytic metabolite bypasses "two-hit" tumor suppression by BRCA2.

Knudson's "two-hit" paradigm posits that carcinogenesis requires inactivation of both copies of an autosomal tumor suppressor gene. Here, we report that the glycolytic metabolite methylglyoxal (MGO) transiently bypasses Knudson's paradigm by inactivating the breast cancer suppressor protein BRCA2 to elicit a cancer-associated, mutational single-base substitution (SBS) signature in nonmalignant mammary cells or patient-derived organoids. Germline monoallelic BRCA2 mutations predispose to these changes. An analogous SBS signature, again without biallelic BRCA2 inactivation, accompanies MGO accumulation and DNA damage in Kras-driven, Brca2-mutant murine pancreatic cancers and human breast cancers. MGO triggers BRCA2 proteolysis, temporarily disabling BRCA2's tumor suppressive functions in DNA repair and replication, causing functional haploinsufficiency. Intermittent MGO exposure incites episodic SBS mutations without permanent BRCA2 inactivation. Thus, a metabolic mechanism wherein MGO-induced BRCA2 haploinsufficiency transiently bypasses Knudson's two-hit requirement could link glycolysis activation by oncogenes, metabolic disorders, or dietary challenges to mutational signatures implicated in cancer evolution.

High-throughput surface marker screen on primary human breast tissues reveals further cellular heterogeneity.

BACKGROUND: Normal human breast tissues are a heterogeneous mix of epithelial and stromal subtypes in different cell states. Delineating the spectrum of cellular heterogeneity will provide new insights into normal cellular properties within the breast tissue that might become dysregulated in the initial stages of cancer. Investigation of surface marker expression provides a valuable approach to resolve complex cell populations. However, the majority of cell surface maker expression of primary breast cells have not been investigated. METHODS: To determine the differences in expression of a range of uninvestigated cell surface markers between the normal breast cell subpopulations, primary human breast cells were analysed using high-throughput flow cytometry for the expression of 242 cell surface proteins in conjunction with EpCAM/CD49f staining. RESULTS: We identified 35 surface marker proteins expressed on normal breast epithelial and/or stromal subpopulations that were previously unreported. We also show multiple markers were equally expressed in all cell populations (e.g. CD9, CD59, CD164) while other surface markers were confirmed to be enriched in different cell lineages: CD24, CD227 and CD340 in the luminal compartment, CD10 and CD90 in the basal population, and CD34 and CD140b on stromal cells. CONCLUSIONS: Our dataset of CD marker expression in the normal breast provides better definition for breast cellular heterogeneity.

Androgen Receptor Signalling Promotes a Luminal Phenotype in Mammary Epithelial Cells.

Androgens influence mammary gland development but the specific role of the androgen receptor (AR) in mammary function is largely unknown. We identified cell subsets that express AR in vivo and determined the effect of AR activation and transgenic AR inhibition on sub-populations of the normal mouse mammary epithelium by flow cytometry and immunohistochemistry. Immunolocalisation of AR with markers of lineage identity was also performed in human breast tissues. AR activation in vivo significantly decreased the proportion of basal cells, and caused an accumulation of cells that expressed a basal cell marker but exhibited morphological features of luminal identity. Conversely, in AR null mice the proportion of basal mammary epithelial cells was significantly increased. Inhibition of AR increased basal but not luminal progenitor cell activity in vitro. A small population of AR-positive cells in a basal-to-luminal phenotype transition was also evident in human breast lobules. Collectively, these data support a role for AR in promoting a luminal phenotype in mammary epithelial cells.

Natural outer membrane permeabilizers boost antibiotic action against irradiated resistant bacteria.

BACKGROUND: This study sought to develop new strategies for reverting the resistance of pathogenic Gram-negative bacilli by a combination of conventional antibiotics, potent permeabilizers and natural beta lactamase inhibitors enhancing the activity of various antibiotics. METHODS: The antibiotic susceptibility in the presence of natural non-antibacterial tested concentrations of phytochemicals (permeabilizers and natural beta lactamase inhibitors) was performed by disk diffusion and susceptibility assays. Thymol and gallic acid were the most potent permeabilizers and facilitated the passage of the antibiotics through the outer membrane, as evidenced by their ability to cause LPS release, sensitize bacteria to SDS and Triton X-100. RESULTS: The combination of permeabilizers and natural beta lactamase inhibitors (quercetin and epigallocatechin gallate) with antibiotics induced greater susceptibility of resistant isolates compared to antibiotic treatment with beta lactamase inhibitors alone. Pronounced effects were detected with 24.4 Gy in vitro gamma irradiation on permeability barrier, beta lactamase activity, and outer membrane protein profiles of the tested isolates. CONCLUSIONS: The synergistic effects of the studied natural phytochemicals and antibiotics leads to new clinical choices via outer membrane destabilization (permeabilizers) and/or inactivation of the beta lactamase enzyme, which enables the use of older, more cost-effective antibiotics against resistant strains.

Randomized controlled study of a novel triple nitazoxanide (NTZ)-containing therapeutic regimen versus the traditional regimen for eradication of Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori infection has become more and more resistant to conventional first-line treatment regimens. So, there is a considerable interest in evaluating new antibiotic combinations and regimens. Nitazoxanide is an anti-infective drug with demonstrated activity against protozoa and anaerobic bacteria including H. pylori. This work is designed to evaluate the efficacy and safety of a unique triple nitazoxanide-containing regimen as a treatment regimen in Egyptian patients with H. pylori infection. METHODS: Two hundred and 24 patients with upper gastrointestinal tract (GIT) dyspeptic symptoms in whom H. pylori -induced GIT disease was confirmed were included in the study. They have been randomized to receive either nitazoxanide 500 mg b.i.d., clarithromycin 500 mg b.i.d., and omeprazole 40 mg twice daily for 14 days or metronidazole 500 mg b.i.d., clarithromycin 500 mg b.i.d., and omeprazole 40  mg twice daily for 14 days. Laboratory evaluation for H. pylori antigen within the stool was performed 6 weeks after cessation of H. pylori treatment regimens to assess the response. RESULTS: The response to treatment was significantly higher in group 1 of nitazoxanide treatment regimen than group 2 of traditional treatment regimen. One hundred and six cases (94.6%) of 112 patients who completed the study in group 1 showed complete cure, while only 63 cases (60.6%) of 104 patients who completed the study in group 2 showed the same response according to per-protocol (PP) analysis (P<.001). The regimen was well tolerated by all the patients enrolled in the study. CONCLUSION: Nitazoxanide-containing triple therapy is a promising therapy for the first-line eradication of H. pylori. (ClinicalTrials.gov Identifier: NCT02422706).

The influence of tamoxifen on normal mouse mammary gland homeostasis.

INTRODUCTION: Lineage tracing using inducible genetic labeling has emerged to be a powerful method for interrogating the developmental fate of cells in intact tissues. A common induction mechanism is the use of tamoxifen-dependent Cre recombinase (CreER and CreERT2), but the effects of tamoxifen at doses normally used in lineage-tracing studies on normal adult mammary gland homeostasis are not known. METHODS: We used flow cytometry and immunostaining of intact glands to determine whether varying doses of tamoxifen skew the distribution and the apoptosis and proliferation status of different types of mammary epithelial cells in vivo. We also examined how tamoxifen influences the number of progenitor and mammary repopulating units (MRUs). RESULTS: Our results indicate that ≥5 mg/25 g body weight of tamoxifen induces a transient increase in cell proliferation and in the number of basal cells in the adult mammary epithelium up to 7 days after tamoxifen administration. However, in the medium term (3 weeks), all doses of tamoxifen≥1 mg/25 g body weight result in a decrease in the number of basal and EpCAM+CD49b- luminal cells and a decrease in progenitor cell function. Tamoxifen at doses≥5 mg/25 g body weight induced a transient increase in caspase-3-mediated apoptotic cell death within the mammary epithelium. However, mammary epithelial cell numbers in all subpopulations were restored to their original levels by 8 weeks. No long-lasting effects of tamoxifen on MRU numbers or on pubertal ductal development were observed. CONCLUSION: Tamoxifen can skew the distribution of mammary cell types in a dose-dependent manner, and thus caution must be taken when interpreting lineage-tracing studies using high doses of tamoxifen, particularly when short-duration analyses of a quantitative nature are being performed.

Laparoscopic management of intestinal obstruction in a young adult with a virgin abdomen: Unusual presentation of combined vitellointestinal duct remnants: A clinical case report.

Key Clinical Message: In an 18-year-old, Meckel's diverticulum and a rare vitellointestinal fibrous band caused bowel obstruction. Clinicians should be vigilant for such anomalies, especially in young adults with virgin abdomens, as potential sources of intestinal obstruction. Abstract: In this case report, we highlight the rarity of vitellointestinal or omphalomesenteric duct anomalies causing intestinal obstruction in the adult population. The patient, an 18-year-old male, presented to the emergency department with a two-day history of abdominal pain and vomiting. Physical examination revealed mild distension of his virgin abdomen with generalized tenderness. Abdominal X-ray displayed dilated small bowel loops, and a computed tomography scan indicated features consistent with closed-loop bowel obstruction. Diagnostic laparoscopy confirmed a vitellointestinal duct remnant as the cause of the small intestinal obstruction, involving a combined Meckel's diverticulum and vitellointestinal fibrous band. In early fetal development, the vitellointestinal duct communicates between the midgut and the yolk sac, expected to disappear during fetal growth. Failure to obliterate can lead to issues such as intestinal blockage, primarily observed in children, making occurrences in adults, as in this case, infrequent with only a few documented instances. Despite its uncommon occurrence in young adults, healthcare providers should consider the vitellointestinal duct anomalous remnant as a potential source of intestinal obstruction, particularly in individuals with a virgin abdomen. Early detection of intestinal obstruction is imperative for patient survival, facilitating prompt management and minimizing the risk of serious morbidities, ultimately contributing to a better patient outcome.

Uncommon presentation of complicated internal hernia through the appendices epiploicae ring of adhesion: a clinical case study.

Background: Internal hernias are infrequent, yet serious, medical conditions with potentially severe consequences. An internal hernia resulting from an Appendices epiploicae (AE) ring is an especially rare cause, with a mere nine documented instances worldwide. Case report: This report presents the case of a 58-year-old male who suffered from an internal hernia originating from an AE ring. The condition led to a gangrenous small bowel, which was treated by laparotomy and resection of the affected segment, followed by primary anastomosis. The post-operative recovery was favorable. Conclusion: Internal hernias, although rare, warrant immediate attention and early intervention to preclude detrimental outcomes, as illustrated in this particular case.

A transcriptional response to replication stress selectively expands a subset of Brca2-mutant mammary epithelial cells.

Germline BRCA2 mutation carriers frequently develop luminal-like breast cancers, but it remains unclear how BRCA2 mutations affect mammary epithelial subpopulations. Here, we report that monoallelic Brca2mut/WT mammary organoids subjected to replication stress activate a transcriptional response that selectively expands Brca2mut/WT luminal cells lacking hormone receptor expression (HR-). While CyTOF analyses reveal comparable epithelial compositions among wildtype and Brca2mut/WT mammary glands, Brca2mut/WT HR- luminal cells exhibit greater organoid formation and preferentially survive and expand under replication stress. ScRNA-seq analysis corroborates the expansion of HR- luminal cells which express elevated transcript levels of Tetraspanin-8 (Tspan8) and Thrsp, plus pathways implicated in replication stress survival including Type I interferon responses. Notably, CRISPR/Cas9-mediated deletion of Tspan8 or Thrsp prevents Brca2mut/WT HR- luminal cell expansion. Our findings indicate that Brca2mut/WT cells activate a transcriptional response after replication stress that preferentially favours outgrowth of HR- luminal cells through the expression of interferon-responsive and mammary alveolar genes.

Adult appendicitis score versus Alvarado score: A comparative study in the diagnosis of acute appendicitis.

Background: Acute Appendicitis (AA) is the most common abdominal surgical emergency. It requires proper management to decrease mortality and morbidity. Clinical scoring systems for diagnosing AA aimed to decrease the use of radiological scans and the rate of negative appendectomies (NA). We aim to assess the adult appendicitis score (AAS) in the diagnosis prediction of AA. Method: A retrospective study with 1303 cases of AA is performed. We compared the correlation of AAS and Alvarado scores to postoperative histopathology. Specificity, sensitivity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV) were assessed. ROC was used. Results: AAS risk stratification was applied to the study population. Group I for a low probability, and groups II and III for an intermediate and high probability of AA. We found that 159 patients were matched in group I, 505, and 639 were in groups II and III of AAS, respectively. The correlation between Alvarado and AAS with HP was significant. AAS ≥ 16 presented sensitivity and specificity of 50 % and 75.47 %, respectively, with PPV of 97.96 % and NPV of 6.02 %, with an accuracy of 51.04 %. Regarding AAS ≥ 11, the sensitivity was 88.96 %, specificity was 39.62 %, PPV was 97.2 %, NPV was 13.21 %, and accuracy was 86.95 %. Conclusion: AAS is relatively more accurate than Alvarado's score, especially in selecting a safe candidate for discharge from an emergency. In addition, AAS is found to decrease the need for radiological images and NA rate more than Alvarado.

Phenotypic and functional characterisation of the luminal cell hierarchy of the mammary gland.

INTRODUCTION: The organisation of the mammary epithelial hierarchy is poorly understood. Our hypothesis is that the luminal cell compartment is more complex than initially described, and that an understanding of the developmental relationships within this lineage will help in understanding the cellular context in which breast tumours occur. METHODS: We used fluorescence-activated cell sorting along with in vitro and in vivo functional assays to examine the growth and differentiation properties of distinct subsets of human and mouse mammary epithelial cells. We also examined how loss of steroid hormones influenced these populations in vivo. Gene expression profiles were also obtained for all the purified cell populations and correlated to those obtained from breast tumours. RESULTS: The luminal cell compartment of the mouse mammary gland can be resolved into nonclonogenic oestrogen receptor-positive (ER+) luminal cells, ER+ luminal progenitors and oestrogen receptor-negative (ER-) luminal progenitors. The ER+ luminal progenitors are unique in regard to cell survival, as they are relatively insensitive to loss of oestrogen and progesterone when compared with the other types of mammary epithelial cells. Analysis of normal human breast tissue reveals a similar hierarchical organisation composed of nonclonogenic luminal cells, and relatively differentiated (EpCAM+CD49f+ALDH-) and undifferentiated (EpCAM+CD49f+ALDH+) luminal progenitors. In addition, approximately one-quarter of human breast samples examined contained an additional population that had a distinct luminal progenitor phenotype, characterised by low expression of ERBB3 and low proliferative potential. Parent-progeny relationship experiments demonstrated that all luminal progenitor populations in both species are highly plastic and, at low frequencies, can generate progeny representing all mammary cell types. The ER- luminal progenitors in the mouse and the ALDH+ luminal progenitors in the human appear to be analogous populations since they both have gene signatures that are associated with alveolar differentiation and resemble those obtained from basal-like breast tumours. CONCLUSION: The luminal cell compartment in the mammary epithelium is more heterogeneous than initially perceived since progenitors of varying levels of luminal cell differentiation and proliferative capacities can be identified. An understanding of these cells will be essential for understanding the origins and the cellular context of human breast tumours.

Current strategies with implementation of three-dimensional cell culture: the challenge of quantification.

From growing cells in spheroids to arranging them on complex engineered scaffolds, three-dimensional cell culture protocols are rapidly expanding and diversifying. While these systems may often improve the physiological relevance of cell culture models, they come with technical challenges, as many of the analytical methods used to characterize traditional two-dimensional (2D) cells must be modified or replaced to be effective. Here we review the advantages and limitations of quantification methods based either on biochemical measurements or microscopy imaging. We focus on the most basic of parameters that one may want to measure, the number of cells. Precise determination of this number is essential for many analytical techniques where measured quantities are only meaningful when normalized to the number of cells (e.g. cytochrome p450 enzyme activity). Thus, accurate measurement of cell number is often a prerequisite to allowing comparisons across different conditions (culturing conditions or drug and treatment screening) or between cells in different spatial states. We note that this issue is often neglected in the literature with little or no information given regarding how normalization was performed, we highlight the pitfalls and complications of quantification and call for more accurate reporting to improve reproducibility.

BRCA2 deficiency reveals that oxidative stress impairs RNaseH1 function to cripple mitochondrial DNA maintenance.

Oxidative stress is a ubiquitous cellular challenge implicated in aging, neurodegeneration, and cancer. By studying pathogenic mutations in the tumor suppressor BRCA2, we identify a general mechanism by which oxidative stress restricts mitochondrial (mt)DNA replication. BRCA2 inactivation induces R-loop accumulation in the mtDNA regulatory region and diminishes mtDNA replication initiation. In BRCA2-deficient cells, intracellular reactive oxygen species (ROS) are elevated, and ROS scavengers suppress the mtDNA defects. Conversely, wild-type cells exposed to oxidative stress by pharmacologic or genetic manipulation phenocopy these defects. Mechanistically, we find that 8-oxoguanine accumulation in mtDNA caused by oxidative stress suffices to impair recruitment of the mitochondrial enzyme RNaseH1 to sites of R-loop accrual, restricting mtDNA replication initiation. Thus, oxidative stress impairs RNaseH1 function to cripple mtDNA maintenance. Our findings highlight a molecular mechanism that links oxidative stress to mitochondrial dysfunction and is elicited by the inactivation of genes implicated in neurodegeneration and cancer.

Time-resolved single-cell analysis of Brca1 associated mammary tumourigenesis reveals aberrant differentiation of luminal progenitors.

It is unclear how genetic aberrations impact the state of nascent tumour cells and their microenvironment. BRCA1 driven triple negative breast cancer (TNBC) has been shown to arise from luminal progenitors yet little is known about how BRCA1 loss-of-function (LOF) and concomitant mutations affect the luminal progenitor cell state. Here we demonstrate how time-resolved single-cell profiling of genetically engineered mouse models before tumour formation can address this challenge. We found that perturbing Brca1/p53 in luminal progenitors induces aberrant alveolar differentiation pre-malignancy accompanied by pro-tumourigenic changes in the immune compartment. Unlike alveolar differentiation during gestation, this process is cell autonomous and characterised by the dysregulation of transcription factors driving alveologenesis. Based on our data we propose a model where Brca1/p53 LOF inadvertently promotes a differentiation program hardwired in luminal progenitors, highlighting the deterministic role of the cell-of-origin and offering a potential explanation for the tissue specificity of BRCA1 tumours.

Endoscopic band ligation plus argon plasma coagulation versus scleroligation for eradication of esophageal varices.

BACKGROUND AND AIM: The aim of this study was to evaluate endoscopic band ligation plus argon plasma coagulation versus scleroligation. METHODS: Patients were randomized to: Group I, 50 patients subjected to endoscopic injection sclerotherapy; Group II, 50 patients subjected to variceal band ligation; Group III, 50 patients subjected to combined endoscopic sclerotherapy and band ligation; and Group IV, 50 patients subjected to endoscopic band ligation plus argon plasma coagulation. RESULTS: A comparison of the number of therapeutic sessions showed that group III underwent significantly fewer sessions. As regards post-treatment complications, Group I showed a high incidence of transient pyrexia, transient dysphagia and/or retrosternal pain and ulceration, while in group II a higher incidence of rebleeding was demonstrated, as well as a higher incidence of esophageal varix recurrence after eradication during the follow-up period. A higher mortality incidence was detected in groups I and II. The follow-up incidence did not significantly differ between the different study groups. CONCLUSION: Scleroligation allows very rapid eradication of varices, has a low recurrence rate, avoids the disadvantage of high recurrence of band ligation alone, and does not require special skills over sclerotherapy or band ligation. Also, band ligation plus argon plasma coagulation allows for very rapid eradication of varices, and a low recurrence rate, with no obvious recorded complications, but it has the disadvantage of being the most expensive technique and requires special equipment that is only available in a few endoscopic centers.

Hypervascular Nodules and Stiffer Liver are Associated with Recurrence after Microwave Ablation in Patients with Hepatocellular Carcinoma: A Double-Center Analysis.

Background and Aims The aim of this study was to detect the most important risk factors for recurrence after microwave ablation (MWA) of hepatocellular carcinoma (HCC). Methods A total of 92 patients with 110 HCC focal lesions (FLs) underwent MWA therapy. All the patients underwent triphasic CT before and after 1 and 3 months of MWA therapy. Complete ablation and recurrence rates were recorded, and the risk factors associated with recurrence were analyzed. Results Regarding the 110 HCC FLs that were detected pre-MWA, adequate ablation was recorded post-MWA procedure in 88 FLs (80%) and incomplete ablation in 22 FLs (showed residual contrast enhancement). However, there were newly detected lesions (17 FLs). The rate of recurrence was significantly higher in patients with multiple larger (> 4 cm) sized and hypervascular nodules. Diabetics were significantly associated with a higher recurrence rate of HCC. The rate of recurrence was significantly higher in patients with baseline level of serum alfa-fetoprotein (AFP) ≥200 ng/mL. Stiffer liver> 25 kPa had higher incidence for recurrence after ablation. Conclusion Meticulous follow-up is mandatory in diabetic patients, patients with AFP > 200 ng/dL starting value, hypervascular large hepatic FL, and in stiffer liver> 25 kPa, as these patients have higher incidence for recurrence after ablation.

Study of Toll-like Receptor 3 Gene Polymorphism as a Novel Risk Factor for HCV-related Hepatocellular Carcinoma in Egypt.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is a highly aggressive cancer with few treatment options. Toll-like receptor 3 (TLR3) plays a key role in innate immunity and may affect the development of cancers. This study aimed to investigate the association between TLR3 gene polymorphism and HCV-related hepatocellular carcinoma in Egypt. METHODS: This work was conducted on 70 individuals; fifty HCV cirrhotic patients were included in two groups; with HCC (30 patients) and without HCC (20 patients) compared with a group of 20 apparently healthy controls. All of the studied individuals underwent clinical-laboratory evaluation. TLR3 gene single-nucleotide polymorphism (SNP) (+1234C/T) was tested by polymerase chain reaction- restriction fragment length polymorphism. RESULTS: This study reported that the prevalence of TLR3 +1234TT genotype was significantly increased in cirrhotic patients with HCC than without HCC, while it was not detected at all among the controls. When analyzing the TLR3 SNP +1234C/T with different clinical parameters in HCC patients, there was a significant association between+1234C/T SNP; namely TT genotype and each of the hepatic focal lesionsá¾½ number, size and the patientsá¾½ higher Okuda and BCLC stages. No association could be detected between TLR3 SNP and the age, sex, Child-Pugh grades, MELD score or AFP of the studied HCC cases. CONCLUSION: TLR3 gene SN P +1234C/T could be a novel risk factor for the HCV-related HCC among the Egyptian population.

Mucin 1 (MUC1) is a novel partner for MAL2 in breast carcinoma cells.

BACKGROUND: The MAL2 gene, encoding a four-transmembrane protein of the MAL family, is amplified and overexpressed in breast and other cancers, yet the significance of this is unknown. MAL-like proteins have trafficking functions, but their molecular roles are largely obscure, partly due to a lack of known binding partners. METHODS: Yeast two-hybrid screening of a breast carcinoma cDNA expression library was performed using a full-length MAL2 bait, and subsequent deletion mapping experiments were performed. MAL2 interactions were confirmed by co-immunoprecipitation analyses and confocal microscopy was employed to compare protein sub-cellular distributions. Sucrose density gradient centrifugation of membranes extracted in cold Triton X-100 was employed to compare protein distributions between Triton X-100-soluble and -insoluble fractions. RESULTS: The tumor-associated protein mucin 1 (MUC1) was identified as a potential MAL2 partner, with MAL2/MUC1 interactions being confirmed in myc-tagged MAL2-expressing MCF-10A cells using co-immunoprecipitation assays. Deletion mapping experiments demonstrated a requirement for the first MAL2 transmembrane domain for MUC1 binding, whereas the MAL2 N-terminal domain was required to bind D52-like proteins. Confocal microscopy identified cytoplasmic co-localisation of MUC1 and MAL2 in breast cell lines, and centrifugation of cell lysates to equilibrium in sucrose density gradients demonstrated that MAL2 and MUC1 proteins were co-distributed between Triton X-100-soluble and -insoluble fractions. However co-immunoprecipitation analyses detected MAL2/MUC1 interactions in Triton X-100-soluble fractions only. Myc-MAL2 expression in MCF-10A cells was associated with both increased MUC1 detection within Triton X-100-soluble and -insoluble fractions, and increased MUC1 detection at the cell surface. CONCLUSION: These results identify MUC1 as a novel MAL2 partner, and suggest a role for MAL2 in regulating MUC1 expression and/or localisation.

Nonredundant functions for tumor protein D52-like proteins support specific targeting of TPD52.

PURPOSE: Tumor protein D52 (TPD52 or D52) is frequently overexpressed in breast and other cancers and present at increased gene copy number. It is, however, unclear whether D52 amplification and overexpression target specific functional properties of the encoded protein. EXPERIMENTAL DESIGN: The expression of D52-like genes and MAL2 was compared in breast tissues using quantitative reverse transcription-PCR. The functions of human D52 and D53 genes were then compared by stable expression in BALB/c 3T3 fibroblasts and transient gene knockdown in breast carcinoma cell lines. In situ D52 and MAL2 protein expression was analyzed in breast tissue samples using tissue microarray sections. RESULTS: The D52 (8q21.13), D54 (20q13.33), and MAL2 (8q24.12) genes were significantly overexpressed in breast cancer tissue (n = 95) relative to normal breast (n = 7; P

Effects of gamma-irradiation on antibiotic resistance and diagnostic molecular markers of methicillin-resistant Staphylococcus aureus in Egyptian cancer patients.

Purpose: This in-vitro study aimed to assess in 120 [40 community-acquired (CA-MRSA) & 80 hospital-acquired (HA-MRSA)] isolates from cancer patients whether the transmissible staphylococcal cassette chromosome mec (SCCmec) typing, and the Panton-Valentine leukocidin (PVL) virulence genes detection could be employed as tools for molecular diagnostic purposes to distinguish both methicillin-resistant Staphylococcus aureus (MRSA) categories in radiotherapy treated cancer patients.Materials and methods: SCCmec typing was determined by the combination of the type of the cassette chromosome recombinase genes (ccr) gene complex and the class of the methicillin resistance (mec) gene complex. Besides, a rapid slide latex agglutination test (LAT) and antibiotic resistance spectrum determination before and after irradiation were performed.Results: In the strict sense, with the effect of irradiation; the presence of SCCmec subtypes IVa (22.5% vs. 10.0%), b (47.5% vs. 25.0%), & d (7.5 vs. 2.5%) or type V (15.0% vs. 7.5%) genetic elements and PVL genes (p < .001) were not proved as a signature for CA-MRSA. While, the larger SCCmec types II, and III elements were not detected in 14, and 19 from the 38, and 36 typed HA-MRSA isolates (p < .001), respectively. Remarkable effects on class A & class B mec gene complex and type2, type 3 & type 5 ccr gene complex and an increase in agglutination reaction strength in response to gamma irradiation external stimulus were observed.Conclusions: Different heterogeneous genetic composition with upregulation mecA gene expression was detected after irradiation in the HA- MRSA studied population. CA-MRSA showed remarkable ability to acquire multi-antibiotic resistance after irradiation and propose a novel paradigm for future chemotherapy against the multi-resistant pathogens whose proliferation especially among immunocompromised cancer patients is on the increase.