Craniofacial Morphology in Myostatin-deficient Mice

GDF-8 (myostatin) is a negative growth regulator of skeletal muscle, and myostatin-deficient mice are hypermuscular. Muscle size and force production are thought to influence growth of the craniofacial skeleton. To test this relationship, we compared masticatory muscle size and craniofacial dimensions in myostatin-deficient and wild-type CD-1 control mice. Myostatin-deficient mice had significantly (p < 0.01) greater body (by 18%) and masseter muscle weight (by 83%), compared with wild-type controls. Significant differences (p < 0.05) were noted for cranial vault length, maxillary length, mandibular body length, and mandibular shape index. Significant correlations were noted between masseter muscle weight and mandibular body length (r = 0.68; p < 0.01), cranial vault length (r = −0.57; p < 0.05), and the mandibular shape index (r = −0.56; p < 0.05). Masticatory hypermuscularity resulted in significantly altered craniofacial morphology, probably through altered biomechanical stress. These findings emphasize the important role that masticatory muscle function plays in the ontogeny of the cranial vault, the maxilla, and, most notably, the mandible.

Epidermal growth factor-like domain 7 promotes migration and invasion of human trophoblast cells through activation of MAPK, PI3K and NOTCH signaling pathways

Epidermal growth factor-like domain 7 (Egfl7) is a gene that encodes a partially secreted protein and whose expression is largely restricted to the endothelia. We recently reported that EGFL7 is also expressed by trophoblast cells in mouse and human placentas. Here, we investigated the molecular pathways that are regulated by EGFL7 in trophoblast cells. Stable EGFL7 overexpression in a Jeg3 human choriocarcinoma cell line resulted in significantly increased cell migration and invasiveness, while cell proliferation was unaffected. Analysis of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways showed that EGFL7 promotes Jeg3 cell motility by activating both pathways. We show that EGFL7 activates the epidermal growth factor receptor (EGFR) in Jeg3 cells, resulting in downstream activation of extracellular regulated kinases (ERKs). In addition, we provide evidence that EGFL7-triggered migration of Jeg3 cells involves activation of NOTCH signaling. EGFL7 and NOTCH1 are co-expressed in Jeg3 cells, and blocking of NOTCH activation abrogates enhanced migration of Jeg3 cells overexpressing EGFL7. We also demonstrate that signaling through EGFR and NOTCH converged to mediate EGFL7 effects. Reduction of endogenous EGFL7 expression in Jeg3 cells significantly decreased cell migration. We further confirmed that EGFL7 stimulates cell migration by using primary human first trimester trophoblast (PTB) cells overexpressing EGFL7. In conclusion, our data suggest that in trophoblast cells, EGFL7 regulates cell migration and invasion by activating multiple signaling pathways. Our results provide a possible explanation for the correlation between reduced expression of EGFL7 and inadequate trophoblast invasion observed in placentopathies.

Distal and proximal colon cancers differ in terms of molecular, pathological, and clinical features

BACKGROUND

Differences exist between the proximal and distal colon in terms of developmental origin, exposure to patterning genes, environmental mutagens, and gut flora. Little is known on how these differences may affect mechanisms of tumorigenesis, side-specific therapy response or prognosis. We explored systematic differences in pathway activation and their clinical implications.

MATERIALS AND METHODS

Detailed clinicopathological data for 3045 colon carcinoma patients enrolled in the PETACC3 adjuvant chemotherapy trial were available for analysis. A subset of 1404 samples had molecular data, including gene expression and DNA copy number profiles for 589 and 199 samples, respectively. In addition, 413 colon adenocarcinoma from TCGA collection were also analyzed. Tumor side-effect on anti-epidermal growth factor receptor (EGFR) therapy was assessed in a cohort of 325 metastatic patients. Outcome variables considered were relapse-free survival and survival after relapse (SAR).

RESULTS

Proximal carcinomas were more often mucinous, microsatellite instable (MSI)-high, mutated in key tumorigenic pathways, expressed a B-Raf proto-oncogene, serine/threonine kinase (BRAF)-like and a serrated pathway signature, regardless of histological type. Distal carcinomas were more often chromosome instable and EGFR or human epidermal growth factor receptor 2 (HER2) amplified, and more frequently overexpressed epiregulin. While risk of relapse was not different per side, SAR was much poorer for proximal than for distal stage III carcinomas in a multivariable model including BRAF mutation status [N = 285; HR 1.95, 95% CI (1.6-2.4), P < 0.001]. Only patients with metastases from a distal carcinoma responded to anti-EGFR therapy, in line with the predictions of our pathway enrichment analysis.

CONCLUSIONS

Colorectal carcinoma side is associated with differences in key molecular features, some immediately druggable, with important prognostic effects which are maintained in metastatic lesions. Although within side significant molecular heterogeneity remains, our findings justify stratification of patients by side for retrospective and prospective analyses of drug efficacy and prognosis.

A multicenter phase II study of induction CT with FOLFOX-4 and cetuximab followed by RT and cetuximab in locally advanced esophageal cancer (LAEC)

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Background: Preoperative CRT improves the survival of pts with EC when compared with surgery alone. Epidermal growth factor receptor (EGFR) is overexpressed in 30–90% of EC and is associated with poor prognosis, providing the rationale for using the anti-EGFR monoclonal antibody cetuximab (C). The purpose of the study was to investigate the efficacy, toxicity and feasibility of C with FOLFOX- 4 regimen as induction CT followed by C and RT in pts with LAEC in a multicenter setting. Methods: Eligibility criteria: resectable, locally advanced (uT3 or uN1, T4 if deemed resectable) squamous cell carcinoma (SCC) or adenocarcinoma (AC) of the esophagus; staged by EUS, CT and PET scan; age 18–70y; PS <2; normal organ functions.All pts received induction treatment with C at a starting dose of 400 mg/m2 and further weekly infusion at a maintenance dose of 250 mg/m2 and 4 cycles of FOLFOX-4 every two weeks. Post-induction EUS and CT scans were performed, while a PET scan was repeated early before second cycle of CT: pts without PD were given daily RT (180cGy fractions to 5040cGy) with concurrent weekly C. Post RT, EUS plus biopsies, CT scan and PET were performed. At wk 18, pts without PD had esophagectomy. Simons two stage design was used. Primary endpoint was histopathological response rate. Results: Up to December 2008, 40 pts, 30 men, were enrolled from 4 institutions; median age 59 y (35–70y); AC 12; SCC 28; stage II 15, stage III 25 pts. At this time 32/40 pts were evaluable. The most frequent grade 3/4 toxicity of chemoradiotherapy were skin (32%),neutropenia (29%) and esophagitis (9%); 10 pts had no resection (9 progressive disease,1 patient's refusal). Of 22 operated pts, 17 pts (77%) had RO-resection, 5 pts had palliative surgery.2 pts died due to complications after surgery (1 after > 30 days). The pathological response rate was 68 %, with a complete histopathological remission recorded in 6 pts (27%);17 pts (53%) are still alive without residual or recurrent disease. Conclusions: The current findings suggest the feasibility of incorporating cetuximab into a preoperative regimen for LAEC pts and an encouraging antineoplastic activity with 68% histopathological responders.

No significant financial relationships to disclose.

Panitumumab a novel drug in cancer treatment

The epidermal growth factor receptor (EGFR) is a member of the erbB family overexpressed in most of the solid tumors. In cancer cells, the overexpression of EGFR correlates with the development and the progression of tumor. Panitumumab is a fully human monoclonal antibody that blocks the extracellular domain of the EGFR and has not been associated with the formation of any antibodies directed against it. This review summarizes on the preclinical and clinical development of panitumumab in human solid tumors. As bevacizumab and cetuximab have been approved for colorectal cancer because of their improvements in progression-free survival and overall survival when associated with chemotherapy, panitumumab represents an interesting molecule which needs more phase III studies to validate its efficacy.

[New insights in atherosclerosis research: LOX-1, leading actor of cardiovascular diseases]

The OLR1 gene encodes a cell-surface endocytosis receptor (LOX-1) for oxidized low density lipoprotein (OxLDL). LDL is oxidized in vascular endothelial cells to a highly injurious product that results in endothelial cell injury, which is implicated in the development of atherosclerosis. Vascular endothelial cells also internalize and degrade oxLDL though the OLR1 receptor. This receptor is upregulated by ox-LDL itself and by angiotensin II, endothelin, cytokines, and shear stress, important factors of atherosclerosis. This receptor is upregulated in the arteries of hypertensive, dyslipidemic, and diabetic animals. Two independent studies have demonstrated genetic association between polymorphisms in the OLR1 gene and myocardial infarction. Based on genetic and functional studies we propose LOX-1 as a novel biomarker and target in cardiovascular disease diagnosis and prevention.

Weekly docetaxel and capecitabine is not effective in the treatment of advanced gastric cancer: a phase II study

BACKGROUND

Capecitabine and docetaxel have demonstrated preclinical antitumor synergy and activity in advanced gastric cancer. We assessed the clinical activity and the toxicity of weekly docetaxel in combination with capecitabine in untreated patients with advanced gastric cancer.

PATIENTS AND METHODS

A total of 38 patients were treated with docetaxel 36 mg/m2 on days 1, 8, and 15 i.v., plus capecitabine, 625 mg/m2 bid per os on days 5 to 18 repeated every 4 weeks.

RESULTS

All patients were assessable for response to treatment and for toxicity. Major responses were observed in eight patients (21%), with three patients achieving a CR (7.8%) and five showing a PR (13%). The median time to progression was 5.4 months and the overall survival was 7.7 months. The safety profile of this schedule was acceptable with a low rate of myelossuppression, diarrhoea and hand-foot syndrome.

CONCLUSIONS

The combination of docetaxel and capecitabine at the doses and schedule investigated in this study is safe, but does not show significant activity in untreated patients with advanced gastric cancer.

Premalignant disease: the breast

Premalignant disease of the breast is a controversial and evolving area of medical research. Breast cancer remains the number one cause of death in women in the US between the ages of 40 and 55 and ultimately causes about 4% of all deaths in women. Efforts to identify women at increased risk are of tremendous importance both clinically and from an insurance perspective. To make appropriate underwriting decisions, we need to evaluate proposed markers of increased risk with respect to what is known about how they affect short-term and/or long-term mortality.

Underwriting implications of premalignant disease

The study of premalignant disease may hold the promise of cancer prevention and, in some cases, this potential is already being realized. In other instances, however, increased risk of mortality and morbidity has been identified without clear data to guide treatment. This series reviews the current state of information about premalignant disease from the perspective of diagnosis, treatment and underwriting risk. The first article will focus on prostatic intraepithelial neoplasia.