We report that DNA methyltransferase 1 (DNMT1) expression is dysregulated in breast cancer. The elevated protein levels are not a result of increased mRNA levels, but rather an increase in protein ...half-life. We found that DNMT1 protein levels were elevated in breast cancer tissues and in MCF-7 breast cancer cells relative to normal human mammary epithelial cells (HMECs) without a concomitant increase in DNMT1 mRNA or proliferative fraction. Although DNMT1 mRNA levels were properly S-phase-regulated in both cell types, DNMT1 protein levels did not follow S-phase fraction in MCF-7 cells. Rather, an increase in DNMT1 protein stability was found for MCF-7 cells relative to HMECs, and a destruction domain was mapped to the N-terminal 120 amino acids of DNMT1, which was required for its proper ubiquitination and degradation in HMECs. Furthermore, overexpression of DNMT1 with this deleted destruction domain in HMECs resulted in significantly increased genomic 5-methylcytosine levels relative to overexpression of the full-length protein. The regulation of DNMT1 destruction via this domain may be dysfunctional in cancer cells leading to subsequent cytosine hypermethylation in the genome.
Complete response to neoadjuvant therapy, determined by pathologic examination of the resection specimen (pCR), is associated with a favorable outcome in esophageal adenocarcinomas (EAC), but there ...is significant heterogeneity in survival reported within this group. Our aim was to determine predictors of disease recurrence (DR) and survival in EAC patients with pCR to neoadjuvant therapy. A total of 93 EAC patients with pCR to neoadjuvant therapy were identified, and a predetermined set of clinicopathologic variables was examined, including patient age, sex, tumor location, pretreatment tumor size, endoscopic ultrasound T and N stage, histologic tumor type, and grade in pretreatment biopsies. The esophagectomy specimens were evaluated for the extent of sampling of the tumor bed, depth of treatment-related changes, presence of treatment effect in lymph nodes, and the total number of lymph nodes examined. Complete histologic examination of the tumor bed was the most significant predictor of favorable outcome for both DR (hazard ratio HR=0.42; 95% confidence interval CI: 0.21-0.82; P=0.011) and disease-specific mortality (HR=0.40; 95% CI: 0.22-0.70; P<0.01). The presence of a high-grade adenocarcinoma component in pretreatment biopsies (HR=2.19; 95% CI: 1.22-3.94; P<0.01) was associated with a higher disease-specific mortality, and involvement of the gastroesophageal junction (HR=2.37; 95% CI: 1.11-5.06; P=0.026) was associated with a higher rate of DR. Heterogeneity in outcomes for EAC patients with pCR to therapy can be explained by adequacy of histologic examination of the tumor bed, high tumor grade, and involvement of the gastroesophageal junction.
Paraneoplastic thrombocytosis has been associated with adverse outcomes in several cancers, but has not been described in oesophageal adenocarcinoma. The aim of our study was to examine the ...prognostic value of platelet counts in patients with oesophageal adenocarcinoma.
A cohort of 584 patients who underwent oesophagectomy for oesophageal adenocarcinoma was identified. Platelet counts, history of neoadjuvant chemoradiation, and clinicopathological factors such as T and N stage, and overall survival were recorded.
Patients with elevated platelet count (>450,000/μL) had a higher mortality rate than patients with normal platelet count (150,000–450,000/μL) (hazard ratio = 2.60, p = 0.0013). This effect was seen in patients with and without neoadjuvant chemoradiation therapy. Paraneoplastic thrombocytosis was also associated with increased likelihood of lymph node metastasis compared to normal platelet count (69% versus 31%, p < 0.01).
Paraneoplastic thrombocytosis is associated with increased rate of lymph node metastasis and mortality in oesophageal adenocarcinoma. Further studies are needed to examine the mechanisms behind this phenomenon.
- The clinicopathologic and prognostic significance of ARID1A mutation in esophageal adenocarcinoma (EAC) is unknown.
- To determine the morphological correlates and prognostic significance of ...ARID1A-deficient EAC.
- One hundred twenty cases of primary EAC were evaluated for a predetermined set of histologic features and immunohistochemistry for ARID1A, p53, and MLH1 performed on EAC, as well as adjacent Barrett esophagus and Barrett esophagus-associated dysplasia, when feasible. Associations between categorical clinicopathologic variables were analyzed by Fisher exact test, and survival analysis was performed by a Cox proportional hazards analysis.
- The study group included 97 men and 23 women (mean age, 66 years). Loss of ARID1A expression was seen in 12 of 120 EACs (10%). ARID1A-deficient tumors showed a strong correlation with a medullary and mucinous phenotype, and 8 of 12 (67%) had at least one feature reminiscent of high microsatellite instability colon carcinomas (mucinous or medullary differentiation, marked intratumoral or peritumoral lymphoid infiltrate). A mutant p53 pattern was present in 52 of 120 EACs (43%) and showed no correlation with ARID1A deficiency (P > .05). MLH1 loss was present in only 2 of 120 EACs (2%); both of which were also deficient in ARID1A. ARID1A-deficient EACs showed a trend toward increased risk of nodal metastasis but had no effect on overall patient survival.
- ARID1A-deficient EACs show a phenotype similar to colon cancer with high microsatellite instability but do not appear to have any prognostic significance. Concurrent MLH1 loss is not seen in most ARID1A-deficient tumors, suggesting that ARID1A may be a primary driver of carcinogenesis in a subset of EACs.
Induction therapy followed by esophagectomy has become standard for treatment of intermediate-stage esophageal cancer in many centers. Herein we evaluate the feasibility and safety of the 3-hole ...minimally invasive esophagectomy (3HMIE) approach in patients who received induction radiation and chemotherapy. Between 2003 and 2012, the records of 119 consecutive patients with esophageal cancer who underwent 3HMIE were reviewed for perioperative complications and long-term outcomes. Comparison was made between procedures performed for patients receiving neoadjuvant chemoradiation and patients who were treated with only surgery. Of them, 78 patients received neoadjuvant chemoradiation and 41 patients were treated with only surgery. Tumor locations were upper (2), middle (16), distal (64), and gastroesophageal junction (37). In all, 76 patients were at clinical stage IIA or above at presentation. Increased requirement for blood replacement in the induction therapy group was significant compared with the surgery-only group. Operative time, estimated blood loss, proximal and distal margin lengths, and length of stay were not significantly different between the cohorts. There was a 30-day perioperative death (0.8%), and this patient was from the surgery-only group. No conduit necrosis or need for diversion was recorded. Overall, 5-year survival was 62% among the 107 patients with early-stage esophageal cancer. 3HMIE is feasible with low mortality and acceptable morbidity even in patients with locally advanced esophageal cancer who received neoadjuvant radiochemotherapy. Overall perioperative and survival outcomes are similar to or better than those reported in the published literature on esophagectomy after induction therapy.
Biologic agents are effective treatments for rheumatoid arthritis but are associated with important risks, including severe infections. Tumor Necrosis Factor (TNF) α inhibitors are known to increase ...the risk of systemic fungal infections such as disseminated histoplasmosis. Abatacept is a biologic agent with a mechanism different from that of TNFα inhibitors: It suppresses cellular immunity by competing for the costimulatory signal on antigen-presenting cells. The risk of disseminated histoplasmosis for patients on abatacept is not known. We report a case of abatacept-associated disseminated histoplasmosis and review the known infectious complications of abatacept. While the safety of resuming biologic agents following treatment for disseminated histoplasmosis is also not known, abatacept is recommended over TNFα inhibitors for rheumatoid arthritis patients with a prior serious infection. We discuss the evidence supporting this recommendation and discuss alternative treatments for rheumatoid arthritis patients with a history of a serious infection.
Human prostatic carcinogenesis is characterized by the accumulation of both genetic and epigenetic alterations. The epigenetic changes appear earlier and more consistently, and because the DNA ...sequence remains intact, may be therapeutically reversible. The mechanism(s) by which epigenetic changes appear during the pathogenesis of prostate cancer have not been established. Nonetheless, new methods for the detection of abnormal DNA methylation, a molecular biomarker of epigenetic alterations, are poised to provide clinical tests potentially useful for prostate cancer detection and diagnosis. In addition, new drugs targeting DNA methyltransferases and other enzymes involved in the maintenance of chromatic structure have been introduced into clinical trials for the treatment of advanced prostate cancers. If sufficiently safe strategies for chromatin modulation can be discovered and developed, epigenetic alterations may become rational targets for both prostate cancer prevention and prostate cancer treatment.
Huang Q, Fan X, Agoston A T, Feng A, Yu H, Lauwers G, Zhang L & Odze R D (2011) Histopathology59, 188–197
Comparison of gastro‐oesophageal junction carcinomas in Chinese versus American patients
...Aims: To compare the clinical and pathological features of gastro‐oesophageal junction (GEJ) carcinomas in Chinese and American patients.
Methods and results: Eighty consecutive patients with a GEJ carcinoma (43 from mainland China, and 37 from the USA) were evaluated for association with Barrett oesophagus (BO), chronic Helicobacter pylori gastritis, intestinal metaplasia, and outcome. GEJ carcinomas were defined as tumours that were located within 20 mm of, and crossed, the GEJ. Overall, GEJ carcinomas from Chinese patients revealed significantly more frequent location in the proximal stomach, higher pathological stage, larger size, younger patient age, and association with chronic H. pylori gastritis. In contrast, GEJ cancers from American patients showed a strong association with distal oesophageal location, BO, and associated intestinal metaplasia and dysplasia. Pathologically, GEJ carcinomas from American patients were predominantly adenocarcinomas, whereas Chinese patients showed a higher proportion of mucinous, adenosquamous, acinar or neuroendocrine tumours. Overall, 3‐ and 5‐year survival rates were statistically similar between both patient groups, but upon multivariate analysis, Chinese patients showed statistically better survival rates for stage III tumours.
Conclusions: Most GEJ carcinomas in patients from China represent proximal gastric cancers associated with chronic H. pylori gastritis, and BO‐associated carcinomas are rare among this patient population.
Metaplastic epithelial cells of Barrett's esophagus transformed by the combination of p53-knockdown and oncogenic Ras expression are known to activate signal transducer and activator of transcription ...3 (STAT3). When phosphorylated at tyrosine 705 (Tyr705), STAT3 functions as a nuclear transcription factor that can contribute to oncogenesis. STAT3 phosphorylated at serine 727 (Ser727) localizes in mitochondria, but little is known about mitochondrial STAT3's contribution to carcinogenesis in Barrett's esophagus, which is the focus of this study. We introduced a constitutively active variant of human STAT3 (STAT3CA) into the following: 1) non-neoplastic Barrett's (BAR-T) cells; 2) BAR-T cells with p53 knockdown; and 3) BAR-T cells that express oncogenic H-Ras(G12V). STAT3CA transformed only the H-Ras(G12V)-expressing BAR-T cells (evidenced by loss of contact inhibition, formation of colonies in soft agar, and generation of tumors in immunodeficient mice), and did so in a p53-independent fashion. The transformed cells had elevated levels of both mitochondrial (Ser727) and nuclear (Tyr705) phospho-STAT3. Introduction of a STAT3CA construct with a mutated tyrosine phosphorylation site into H-Ras(G12V)-expressing Barrett's cells resulted in high levels of mitochondrial phospho-STAT3 (Ser727) with little or no nuclear phospho-STAT3 (Tyr705), and the cells still formed tumors in immunodeficient mice. Thus tyrosine phosphorylation of STAT3 is not required for tumor formation in Ras-expressing Barrett's cells. We conclude that mitochondrial STAT3 (Ser727) can contribute to oncogenesis in Barrett's cells that express oncogenic Ras. These findings suggest that agents targeting STAT3 might be useful for chemoprevention in patients with Barrett's esophagus.
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