Inhibition of the Intrinsic but Not the Extrinsic Apoptosis Pathway Accelerates and Drives Myc-Driven Tumorigenesis Towards Acute Myeloid Leukemia

Myc plays an important role in tumor development, including acute myeloid leukemia (AML). However, MYC is also a powerful inducer of apoptosis, which is one of the major failsafe programs to prevent cancer development. To clarify the relative importance of the extrinsic (death receptor-mediated) versus the intrinsic (mitochondrial) pathway of apoptosis in MYC-driven AML, we coexpressed MYC together with anti-apoptotic proteins of relevance for AML; BCL-XL/BCL-2 (inhibiting the intrinsic pathway) or FLIPL (inhibiting the extrinsic pathway), in hematopoietic stems cells (HSCs). Transplantation of HSCs expressing MYC into syngeneic recipient mice resulted in development of AML and T-cell lymphomas within 7–9 weeks as expected. Importantly, coexpression of MYC together with BCL-XL/BCL-2 resulted in strongly accelerated kinetics and favored tumor development towards aggressive AML. In contrast, coexpression of MYC and FLIPL did neither accelerate tumorigenesis nor change the ratio of AML versus T-cell lymphoma. However, a change in distribution of immature CD4+CD8+ versus mature CD4+ T-cell lymphoma was observed in MYC/FLIPL mice, possibly as a result of increased survival of the CD4+ population, but this did not significantly affect the outcome of the disease. In conclusion, our findings provide direct evidence that BCL-XL and BCL-2 but not FLIPL acts in synergy with MYC to drive AML development

Analysis of the candidate 8p21 tumour suppressor, BNIP3L, in breast and ovarian cancer

Loss of heterozygosity (LOH) on the short arm of chromosome 8, at 8p 12-p23, is one of the most frequent genetic events in both breast and ovarian cancer, suggesting the location of a shared tumour suppressor gene. Microcell-mediated chromosome transfer of chromosome 8 suppresses tumorigenicity and growth of colorectal and prostate cancer cell lines, further supporting the presence of a tumour suppressor gene on 8p. We have taken a candidate gene approach to try to identify this tumour suppressor gene at 8p 12-p23. BNIP3L, which has sequence homology to pro-apoptotic proteins and the ability to suppress colony formation in soft agar, is located at 8p21, within a region of ovarian cancer LOH, breast cancer LOH and prostate cancer metastasis suppression. BNIP3L expression was assessed by both RT-PCR and Northern blot analysis in breast and ovarian cancer cell lines and found to be expressed at similar levels relative to expression in their respective normal epithelial cell lines. Genetic analysis of BNIP3L in 40 primary ovarian and 25 primary breast tumours identified one somatic, intronic mutation in one ovarian tumour, as well as several polymorphisms, including one resulting in an amino-acid substitution. These data suggest that BNIP3L is unlikely to be the target of 8p LOH in ovarian or breast cancer

Natural orifice surgery: initial clinical experience

Natural orifice translumenal endoscopic surgery (NOTES) has moved quickly from preclinical investigation to clinical implementation. However, several major technical problems limit clinical NOTES including safe access, retraction and dissection of the gallbladder, and clipping of key structures. This study aimed to identify challenges and develop solutions for NOTES during the initial clinical experience. Under an Institutional Review Board (IRB)-approved protocol, patients consented to a natural orifice operation for removal of either the gallbladder or the appendix via either the vagina or the stomach using a single umbilical trocar for safety and assistance. Nine transvaginal cholecystectomies, one transgastric appendectomy, and one transvaginal appendectomy have been completed to date. All but one patient were discharged on postoperative day 1 as per protocol. No complications occurred. The limited initial evidence from this study demonstrates that NOTES is feasible and safe. The addition of an umbilical trocar is a bridge allowing safe performance of NOTES procedures until better instruments become available. The addition of a flexible long grasper through the vagina and a flexible operating platform through the stomach has enabled the performance of NOTES in a safe and easily reproducible manner. The use of a uterine manipulator has facilitated visualization of the cul de sac in women with a uterus to allow for safe transvaginal access

Gene expression profile of cervical and skin tissues from human papillomavirus type 16 E6 transgenic mice

<p>Abstract</p> <p>Background</p> <p>Although K14E6 transgenic mice develop spontaneous tumors of the skin epithelium, no spontaneous reproductive tract malignancies arise, unless the transgenic mice were treated chronically with 17β-estradiol. These findings suggest that E6 performs critical functions in normal adult cervix and skin, highlighting the need to define E6-controlled transcriptional programs in these tissues.</p> <p>Methods</p> <p>We evaluated the expression profile of 14,000 genes in skin or cervix from young K14E6 transgenic mice compared with nontransgenic. To identify differentially expressed genes a linear model was implemented using R and the LIMMA package. Two criteria were used to select the set of relevant genes. First a set of genes with a Log-odds ≥ 3 were selected. Then, a hierarchical search of genes was based on Log Fold Changes.</p> <p>Results</p> <p>Microarray analysis identified a total of 676 and 1154 genes that were significantly up and down-regulated, respectively, in skin from K14E6 transgenic mice. On the other hand, in the cervix from K14E6 transgenic mice we found that only 97 and 252 genes were significantly up and down-regulated, respectively. One of the most affected processes in the skin from K14E6 transgenic mice was the cell cycle. We also found that skin from transgenic mice showed down-regulation of pro-apoptotic genes and genes related to the immune response. In the cervix of K14E6 transgenic mice, we could not find affected any gene related to the cell cycle and apoptosis pathways but did observe alterations in the expression of immune response genes. Pathways such as angiogenesis, cell junction and epidermis development, also were altered in their gene expression profiles in both tissues.</p> <p>Conclusion</p> <p>Expression of the HPV16 E6 oncoprotein in our model alters expression of genes that fell into several functional groups providing insights into pathways by which E6 deregulate cell cycle progression, apoptosis, the host resistance to infection and immune function, providing new opportunities for early diagnostic markers and therapeutic drug targets.</p

Integrated genomic characterization of oesophageal carcinoma

Oesophageal cancers are prominent worldwide; however, there are few targeted therapies and survival rates for these cancers remain dismal. Here we performed a comprehensive molecular analysis of 164 carcinomas of the oesophagus derived from Western and Eastern populations. Beyond known histopathological and epidemiologic distinctions, molecular features differentiated oesophageal squamous cell carcinomas from oesophageal adenocarcinomas. Oesophageal squamous cell carcinomas resembled squamous carcinomas of other organs more than they did oesophageal adenocarcinomas. Our analyses identified three molecular subclasses of oesophageal squamous cell carcinomas, but none showed evidence for an aetiological role of human papillomavirus. Squamous cell carcinomas showed frequent genomic amplifications of CCND1 and SOX2 and/or TP63, whereas ERBB2, VEGFA and GATA4 and GATA6 were more commonly amplified in adenocarcinomas. Oesophageal adenocarcinomas strongly resembled the chromosomally unstable variant of gastric adenocarcinoma, suggesting that these cancers could be considered a single disease entity. However, some molecular features, including DNA hypermethylation, occurred disproportionally in oesophageal adenocarcinomas. These data provide a framework to facilitate more rational categorization of these tumours and a foundation for new therapies.ope

Integrated genomic characterization of oesophageal carcinoma

Oesophageal cancers are prominent worldwide; however, there are few targeted therapies and survival rates for these cancers remain dismal. Here we performed a comprehensive molecular analysis of 164 carcinomas of the oesophagus derived from Western and Eastern populations. Beyond known histopathological and epidemiologic distinctions, molecular features differentiated oesophageal squamous cell carcinomas from oesophageal adenocarcinomas. Oesophageal squamous cell carcinomas resembled squamous carcinomas of other organs more than they did oesophageal adenocarcinomas. Our analyses identified three molecular subclasses of oesophageal squamous cell carcinomas, but none showed evidence for an aetiological role of human papillomavirus. Squamous cell carcinomas showed frequent genomic amplifications of CCND1 and SOX2 and/or TP63, whereas ERBB2, VEGFA and GATA4 and GATA6 were more commonly amplified in adenocarcinomas. Oesophageal adenocarcinomas strongly resembled the chromosomally unstable variant of gastric adenocarcinoma, suggesting that these cancers could be considered a single disease entity. However, some molecular features, including DNA hypermethylation, occurred disproportionally in oesophageal adenocarcinomas. These data provide a framework to facilitate more rational categorization of these tumours and a foundation for new therapies