Little is known about the biological mechanisms underlying the excess medical morbidity and mortality associated with mood disorders. Substantial evidence supports abnormalities in stress-related ...biological systems in depression. Accelerated telomere shortening may reflect stress-related oxidative damage to cells and accelerated aging, and severe psychosocial stress has been linked to telomere shortening. We propose that chronic stress associated with mood disorders may contribute to excess vulnerability for diseases of aging such as cardiovascular disease and possibly some cancers through accelerated organismal aging.
Telomere length was measured by Southern Analysis in 44 individuals with chronic mood disorders and 44 nonpsychiatrically ill age-matched control subjects.
Telomere length was significantly shorter in those with mood disorders, representing as much as 10 years of accelerated aging.
These results provide preliminary evidence that mood disorders are associated with accelerated aging and may suggest a novel mechanism for mood disorder-associated morbidity and mortality.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Somatic mutations that activate phosphoinositide 3-kinase (PI3K) have been identified in the p110-α catalytic subunit (encoded by PIK3CA). They are most frequently observed in two hotspots: the ...helical domain (E545K and E542K) and the kinase domain (H1047R). Although the p110-α mutants are transforming in vitro, their oncogenic potential has not been assessed in genetically engineered mouse models. Furthermore, clinical trials with PI3K inhibitors have recently been initiated, and it is unknown if their efficacy will be restricted to specific, genetically defined malignancies. In this study, we engineered a mouse model of lung adenocarcinomas initiated and maintained by expression of p110-α H1047R. Treatment of these tumors with NVP-BEZ235, a dual pan-PI3K and mammalian target of rapamycin (mTOR) inhibitor in clinical development, led to marked tumor regression as shown by positron emission tomography-computed tomography, magnetic resonance imaging and microscopic examination. In contrast, mouse lung cancers driven by mutant Kras did not substantially respond to single-agent NVP-BEZ235. However, when NVP-BEZ235 was combined with a mitogen-activated protein kinase kinase (MEK) inhibitor, ARRY-142886, there was marked synergy in shrinking these Kras-mutant cancers. These in vivo studies suggest that inhibitors of the PI3K-mTOR pathway may be active in cancers with PIK3CA mutations and, when combined with MEK inhibitors, may effectively treat KRAS mutated lung cancers.
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DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Purpose
Lynch syndrome and chronic inflammatory bowel disease are two important risk factors for colorectal cancer. It is unclear whether Lynch syndrome patients with inflammatory bowel disease are ...at sufficiently increased risk for colorectal cancer to warrant prophylactic colectomy. This study aims to identify all cases of Lynch syndrome and concurrent inflammatory bowel disease in a large familial gastrointestinal cancer registry, define incidence of colorectal cancer, and characterize mismatch repair protein gene mutation status and inflammatory bowel disease-associated colorectal cancer risk factors.
Methods
We retrospectively identified and collected clinical data for all cases with confirmed diagnoses of Lynch syndrome and inflammatory bowel disease in the Familial Gastrointestinal Cancer Registry at Mount Sinai Hospital in Toronto, Canada.
Results
Twelve cases of confirmed Lynch syndrome, and concurrent inflammatory bowel disease were identified. Four cases developed colorectal cancer. An additional five cases had colectomy; one was performed for severe colitis, and four were performed for low-grade dysplasia. None of these surgical specimens contained malignancy or high-grade dysplasia.
Conclusions
The presentation of Lynch syndrome with inflammatory bowel disease is uncommon and not well described in the literature. This small but important series of twelve cases is the largest reported to date. In this series, patients with Lynch syndrome and concurrent inflammatory bowel disease do not appear to have sufficiently increased risk for colorectal cancer to recommend prophylactic surgery. Therefore, the decision to surgery should continue to be guided by surgical indications for each disease. Further evaluation of this important area will require multi-institutional input.
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EMUNI, FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UL, UM, UPUK, VKSCE, ZAGLJ
To understand the role of human epidermal growth factor receptor (
hEGFR) kinase domain mutations in lung tumorigenesis and response to EGFR-targeted therapies, we generated bitransgenic mice with ...inducible expression in type II pneumocytes of two common hEGFR mutants seen in human lung cancer. Both bitransgenic lines developed lung adenocarcinoma after sustained hEGFR mutant expression, confirming their oncogenic potential. Maintenance of these lung tumors was dependent on continued expression of the EGFR mutants. Treatment with small molecule inhibitors (erlotinib or HKI-272) as well as prolonged treatment with a humanized anti-hEGFR antibody (cetuximab) led to dramatic tumor regression. These data suggest that persistent EGFR signaling is required for tumor maintenance in human lung adenocarcinomas expressing EGFR mutants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva) have shown anti-tumor activity in the treatment of non-small cell lung cancer (NSCLC). Dramatic and durable responses have ...occurred in NSCLC tumors with mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR). In contrast, these inhibitors have shown limited efficacy in glioblastoma, where a distinct EGFR mutation, the variant III (vIll) in-frame deletion of exons 2-7, is commonly found. In this study, we determined that EGFRvlII mutation was present in 5% (3/56) of analyzed human lung squamous cell carcinoma (SCC) but was not present in human lung adenocarcinoma (0/123). We analyzed the role of the EGFRvll mutation in lung tumorigenesis and its response to tyrosine kinase inhibition. Tissue-specific expression of EGFRvIIi in the murine lung led to the development of NSCLC. Most importantly, these lung tumors depend on EGFRvIII expression for maintenance. Treatment with an irreversible EGFR inhibitor, HKI272, dramatically reduced the size of these EGFRvll-driven murine tumors in 1 week. Similarly, Ba/F3 cells transformed with the EGFRvlII mutant were relatively resistant to gefitinib and erlotinib in vitro but proved sensitive to HKI-272. These findings suggest a therapeutic strategy for cancers harboring the EGFRvIII mutation.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The epidermal growth factor receptor (EGFR) secondary kinase domain T790M non-small cell lung cancer (NSCLC) mutation enhances receptor catalytic activity and confers resistance to the reversible ...tyrosine kinase inhibitors gefitinib and erlotinib. Currently, irreversible inhibitors represent the primary approach in clinical use to circumvent resistance. We show that higher concentrations of the irreversible EGFR inhibitor CL-387,785 are required to inhibit EGFR phosphorylation in T790M-expressing cells compared with EGFR mutant NSCLC cells without T790M. Additionally, CL-387,785 does not fully suppress phosphorylation of other activated receptor tyrosine kinases (RTK) in T790M-expressing cells. These deficiencies result in residual Akt and mammalian target of rapamycin (mTOR) activities. Full suppression of EGFR-mediated signaling in T790M-expressing cells requires the combination of CL-387,785 and rapamycin. In contrast, Hsp90 inhibition overcomes these limitations in vitro and depletes cells of EGFR, other RTKs, and phospho-Akt and inhibits mTOR signaling whether or not T790M is present. EGFR-T790M-expressing cells rendered resistant to CL-387,785 by a kinase switch mechanism retain sensitivity to Hsp90 inhibition. Finally, Hsp90 inhibition causes regression in murine lung adenocarcinomas driven by mutant EGFR (L858R) with or without T790M. However, efficacy in the L858R-T790M model requires a more intense treatment schedule and responses were transient. Nonetheless, these findings suggest that Hsp90 inhibitors may be effective in T790M-expressing cells and offer an alternative therapeutic strategy for this subset of lung cancers.
Mutations in the BRAF and KRAS genes occur in approximately 1% to 2% and 20% to 30% of non-small-cell lung cancer patients, respectively, suggesting that the mitogen-activated protein kinase (MAPK) ...pathway is preferentially activated in lung cancers. Here, we show that lung-specific expression of the BRAF V600E mutant induces the activation of extracellular signal-regulated kinase (ERK)-1/2 (MAPK) pathway and the development of lung adenocarcinoma with bronchioloalveolar carcinoma features in vivo. Deinduction of transgene expression led to dramatic tumor regression, paralleled by dramatic dephosphorylation of ERK1/2, implying a dependency of BRAF-mutant lung tumors on the MAPK pathway. Accordingly, in vivo pharmacologic inhibition of MAPK/ERK kinase (MEK; MAPKK) using a specific MEK inhibitor, CI-1040, induced tumor regression associated with inhibition of cell proliferation and induction of apoptosis in these de novo lung tumors. CI-1040 treatment also led to dramatic tumor shrinkage in murine lung tumors driven by a mutant KRas allele. Thus, somatic mutations in different signaling intermediates of the same pathway induce exquisite dependency on a shared downstream effector. These results unveil a potential common vulnerability of BRAF and KRas mutant lung tumors that potentially affects rational deployment of MEK targeted therapies to non-small-cell lung cancer patients.
Purpose: Current therapy for lung cancer involves multimodality therapies. However, many patients are either refractory to therapy
or develop drug resistance. KRAS and epidermal growth factor ...receptor ( EGFR ) mutations represent some of the most common mutations in lung cancer, and many studies have shown the importance of these
mutations in both carcinogenesis and chemoresistance. Genetically engineered murine models of mutant EGFR and KRAS have been developed that more accurately recapitulate human lung cancer. Recently, using cell-based experiments, we showed
that platinum-based drugs and the antidiabetic drug rosiglitazone (PPARγ ligand) interact synergistically to reduce cancer
cell and tumor growth. Here, we directly determined the efficacy of the PPARγ/carboplatin combination in these more relevant
models of drug resistant non–small cell lung cancer.
Experimental Design: Tumorigenesis was induced by activation of either mutant KRAS or EGFR . Mice then received either rosiglitazone or carboplatin monotherapy, or a combination of both drugs. Change in tumor burden,
pathology, and evidence of apoptosis and cell growth were assessed.
Results: Tumor burden remained unchanged or increased in the mice after monotherapy with either rosiglitazone or carboplatin. In striking
contrast, we observed significant tumor shrinkage in mice treated with these drugs in combination. Immunohistochemical analyses
showed that this synergy was mediated via both increased apoptosis and decreased proliferation. Importantly, this synergy
between carboplatin and rosiglitazone did not increase systemic toxicity.
Conclusions: These data show that the PPARγ ligand/carboplatin combination is a new therapy worthy of clinical investigation in lung cancers,
including those cancers that show primary resistance to platinum therapy or acquired resistance to targeted therapy.
Surgical site infections (SSIs) are a significant cause of postoperative morbidity with laparoscopic surgery associated with lower SSI rates. However, a departmental change in our unit to increased ...laparoscopic colorectal surgery resulted in increased wound infection rates at umbilical specimen extraction sites, the cause of which we attempted to elucidate.
Prospectively collected data over an 18-month period (April 2008 to September 2009) for laparoscopic colorectal operations in a busy teaching hospital were retrospectively analysed, focusing on operation performed, whether pre-operative skin cleansing was employed, nature of specimen extraction excision, and rate of umbilical wound infection. Comparison was made with open colorectal procedures performed in the preceding year.
In total, 275 laparoscopic colorectal operations were performed. Over the first 8 months there was a significant increase in infection rates when compared with open procedures over a similar time period (23.5% vs 8.0%; P = 0.0001). Changing practice to use pre-operative skin cleansing and an incision that skirted around, as opposed to traversing, the umbilicus reduced umbilical infection rates significantly from 23.5% to 11.6% (P = 0.01). Patients undergoing right hemicolectomy benefitted more (reduction of 30.0% to 6.9%; P = 0.04) than those undergoing anterior resection (26.8% vs 15.6%, P = 0.13).
Umbilical incisions, when extended for specimen extraction, are particularly prone to infection following colorectal surgery but rates can be reduced by simple measures such as pre-operative umbilical cleansing and avoidance of the umbilicus in the incision, without the need for drastic and costly changes in technique or antibiotic prophylaxis.
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