Global histone modification fingerprinting in human cells using epigenetic reverse phase protein array

The balance between acetylation and deacetylation of histone proteins plays a critical role in the regulation of genomic functions. Aberrations in global levels of histone modifications are linked to carcinogenesis and are currently the focus of intense scrutiny and translational research investments to develop new therapies, which can modify complex disease pathophysiology through epigenetic control. However, despite significant progress in our understanding of the molecular mechanisms of epigenetic machinery in various genomic contexts and cell types, the links between epigenetic modifications and cellular phenotypes are far from being clear. For example, enzymes controlling histone modifications utilize key cellular metabolites associated with intra- and extracellular feedback loops, adding a further layer of complexity to this process. Meanwhile, it has become increasingly evident that new assay technologies which provide robust and precise measurement of global histone modifications are required, for at least two pressing reasons: firstly, many approved drugs are known to influence histone modifications and new cancer therapies are increasingly being developed towards targeting histone deacetylases (HDACs) and other epigenetic readers and writers. Therefore, robust assays for fingerprinting the global effects of such drugs on preclinical cell, organoid and in vivo models is required; and secondly, robust histone-fingerprinting assays applicable to patient samples may afford the development of next-generation diagnostic and prognostic tools. In our study, we have used a panel of monoclonal antibodies to determine the relative changes in the global abundance of post-translational modifications on histones purified from cancer cell lines treated with HDAC inhibitors using a novel technique, called epigenetic reverse phase protein array. We observed a robust increase in acetylation levels within 2–24 h after inhibition of HDACs in different cancer cell lines. Moreover, when these cells were treated with N-acetylated amino acids in addition to HDACs, we detected a further increase in histone acetylation, demonstrating that these molecules could be utilized as donors of the acetyl moiety for protein acetylation. Consequently, this study not only offers a novel assay for diagnostics and drug screening but also warrants further research of the novel class of inexpensive, non-toxic natural compounds that could potentiate the effects of HDAC inhibitors and is therefore of interest for cancer therapeutics

Tratamento de cisto mesentérico quiloso Mesenteric chylous cyst treatment

INTRODUÇÃO: Cistos mesentéricos são tumores abdominais raros, que podem acometer pacientes de todas as faixas etárias, sendo mais comuns em mulheres na quarta década de vida. Essas neoplasias são geralmente assintomáticas e diagnosticadas por acaso. Seu tratamento é baseado na retirada do cisto, por laparotomia ou laparoscopia, embora em alguns casos possa ser necessária a ressecção de segmento intestinal. O prognóstico é bom e a recorrência é baixa. RELATO DO CASO: Mulher de 40 anos de idade, obesa, hipertensa e diabética, apresentou história de dor abdominal contínua de pouca intensidade no hipocôndrio esquerdo e epigástrio, sem irradiações, durante cerca de três meses. Após um mês do início dos sintomas percebeu massa em andar superior do abdome palpável desde o epigástrio até o flanco esquerdo, de consistência endurecida, pouco móvel, superfície regular e dolorosa. A tomografia computadorizada de abdome evidenciou formação cística de paredes finas e lisas, medindo 12,9 x 11,6 x 9,9 cm, situada em flanco esquerdo, em região mesentérica, deslocando estruturas adjacentes, sugestiva de cisto mesentérico. À laparotomia evidenciou-se massa cística, com aproximadamente 10 cm de diâmetro, de parede fina e lisa, cor amarelada, com vasos tortuosos na superfície, sem aderência à estruturas adjacentes, localizada no mesojejuno a cerca de 50 cm da flexura duodenojejunal. O cisto foi completamente retirado e seu conteúdo era líquido brancacento e inodor, sugestivo de quilo. O exame anatomopatológico revelou cisto mesotelial benigno mesentérico. CONCLUSÃO: O tratamento desses cistos consiste basicamente na sua retirada ou descapsulação, que pode ser realizado de preferência por via laparoscópica.<br>INTRODUCTION: Mesenteric cysts are rare abdominal tumors that may occur in patients at any age and are more common in women at the age of forty. They are generally free of symptoms and incidentally found. The treatment is based on cyst ressection, by laparotomy or laparoscopy, although the enterectomy may be necessary. The prognosis is usually good and the recurrence is rare. CASE REPORT: Women 40 years of age, obese, hypertensive and diabetic, had a history of continuous abdominal pain of low intensity in the left hypochondrium and epigastrium, without irradiation, for about three months. After a month of onset of symptoms noticed a mass in the upper abdomen palpable from the epigastrium to the left flank with a hard consistency, little mobility, smooth surface and painful. Computed tomography of the abdomen showed cystic formation with thin smooth wall, measuring 12.9 x 11.6 x 9.9 cm, located on the left flank in the mesenteric region, displacing adjacent structures, suggestive of mesenteric cyst. At laparotomy a cystic mass was found, with approximately 10 cm in diameter, yellowish, with tortuous vessels on the surface, without adherence to adjacent structures, located in mesojejunum about 50 cm from the duodenojejunal flexure. The cyst was completely removed and its content was whitish and odorless liquid, suggesting a chylo. Pathology revealed benign mesothelial mesenteric cyst. CONCLUSION: - The treatment of these cysts consists basically of their withdrawal or decapsulization, which can preferably be achieved by laparoscopy

KRAS and Combined KRAS/TP53 Mutations in Locally Advanced Rectal Cancer are Independently Associated with Decreased Response to Neoadjuvant Therapy

BACKGROUND: The response of rectal cancers to neoadjuvant chemoradiation (CRT) is variable, but tools to predict response remain lacking. We evaluated whether KRAS and TP53 mutations are associated with pathologic complete response (pCR) and lymph node metastasis after adjusting for neoadjuvant regimen. METHODS: Retrospective analysis of 229 pretreatment biopsies from patients with stage II/III rectal cancer was performed. All patients received CRT. Patients received zero to eight cycles of FOLFOX either before or after CRT, but prior to surgical excision. A subset was analyzed to assess concordance between mutation calls by Sanger sequencing and a next-generation assay. RESULTS: 96 (42%) tumors had KRAS mutation, 150 had TP53 mutation (66%), and 59 (26%) had both. 59 patients (26%) achieved pCR following neoadjuvant therapy. 45 of 133 (34%) KRAS wild-type tumors had pCR, compared with 14 of 96 (15%) KRAS mutant tumors (p=0.001). KRAS mutation remained independently associated with a lower pCR rate on multivariable analysis after adjusting for clinical stage, CRT-to-surgery interval, and cycles of FOLFOX (OR 0.34, 95% CI: 0.17-0.66, p < 0.01). Of 29 patients with KRAS G12V or G13D, only 2 (7%) achieved pCR. Tumors with both KRAS and TP53 mutation were associated with lymph node metastasis. The concordance between platforms was high for KRAS (40 of 43, 93%). CONCLUSIONS: KRAS mutation is independently associated with a lower pCR rate in locally advanced rectal cancer after adjusting for variations in neoadjuvant regimen. Genomic data can potentially be used to select patients for “watch and wait” strategies