Lisa Ma

VEGF modulates erythropoiesis through regulation of adult hepatic erythropoietin synthesis

Vascular endothelial growth factor (VEGF) exerts crucial functions during pathological angiogenesis and normal physiology. We observed increased hematocrit (60–75%) after high-grade inhibition of VEGF by diverse methods, including adenoviral expression of soluble VEGF receptor (VEGFR) ectodomains, recombinant VEGF Trap protein and the VEGFR2-selective antibody DC101. Increased production of red blood cells (erythrocytosis) occurred in both mouse and primate models, and was associated with near-complete neutralization of VEGF corneal micropocket angiogenesis. High-grade inhibition of VEGF induced hepatic synthesis of erythropoietin (Epo, encoded by Epo) >40-fold through a HIF-1α–independent mechanism, in parallel with suppression of renal Epo mRNA. Studies using hepatocyte-specific deletion of the Vegfa gene and hepatocyte–endothelial cell cocultures indicated that blockade of VEGF induced hepatic Epo by interfering with homeostatic VEGFR2-dependent paracrine signaling involving interactions between hepatocytes and endothelial cells. These data indicate that VEGF is a previously unsuspected negative regulator of hepatic Epo synthesis and erythropoiesis and suggest that levels of Epo and erythrocytosis could represent noninvasive surrogate markers for stringent blockade of VEGF in vivo.NOTE: In the version of this article initially published, the name of one of the authors, Nihar R. Nayak, was misspelled as Nihar R. Niyak. The error has been corrected in the HTML and PDF versions of the article.

BRAF-mutated, microsatellite-stable adenocarcinoma of the proximal colon: An aggressive adenocarcinoma with poor survival, mucinous differentiation, and adverse morphologic features

The association of BRAF V600E mutation and the presence of the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) often confound analysis of BRAF mutation status and survival in colorectal carcinoma. We evaluated a consecutive series of proximal colonic adenocarcinomas for mismatch repair protein abnormalities/MSI, BRAF V600E mutation, and KRAS mutations in an attempt to determine the prognostic significance of these abnormalities and to correlate histopathologic features with molecular alterations. Of the 259 proximal colon adenocarcinomas analyzed for mismatch repair protein abnormalities and/or MSI, 181 proximal colonic adenocarcinomas demonstrated proficient DNA mismatch repair using either MSI PCR (n=78), mismatch repair protein immunohistochemistry (n=91), or both MSI PCR and mismatch repair immunohistochemistry (n=12); these were tested for the BRAF V600E mutation and KRAS mutations. Compared with BRAF wild-type adenocarcinomas, BRAF-mutated adenocarcinomas more frequently demonstrated adverse histologic features such as lymphatic invasion (16/20, 80% vs. 75/161, 47%; P=0.008), mean number of lymph node metastases (4.5 vs. 2.2; P=0.01), perineural invasion (8/20, 40% vs. 13/161, 8%; P=0.0004), and high tumor budding (16/20, 80% vs. 83/161, 52%; P=0.02). BRAF-mutated adenocarcinomas frequently contained areas with mucinous histology (P=0.0002) and signet ring histology (P=0.03), compared with KRAS-mutated and KRAS/BRAF wild-type adenocarcinomas. Clinical follow-up data were available for 173 proximal colonic adenocarcinomas with proficient DNA mismatch repair. Patients with BRAF-mutated adenocarcinomas had a median survival of 12.3 months with a 1-year probability of survival of 54% and a 1-year disease-free survival of 56%. Patients with KRAS-mutated and KRAS/BRAF wild-type adenocarcinomas had significantly improved overall survival (unadjusted log-rank P=0.03 and unadjusted log-rank P=0.0002, respectively) and disease-free survival (unadjusted log-rank P=0.02 and unadjusted log-rank P=0.02, respectively) compared with patients with BRAF-mutated adenocarcinomas. When adjusting for tumor stage, survival analysis demonstrated that patients with BRAF-mutated adenocarcinoma had a significantly poor overall survival and disease-free survival (hazard ratios 6.63, 95% CI, 2.60-16.94; and 6.08, 95% CI, 2.11-17.56, respectively) compared with patients with KRAS/BRAF wild-type adenocarcinomas. No significant difference in overall or disease-free survival was identified between patients with KRAS-mutated and KRAS/BRAF wild-type adenocarcinomas. Our results demonstrate that BRAF-mutated proximal colon adenocarcinomas with proficient DNA mismatch repair have a dismal prognosis with an aggressive clinical course and often display mucinous differentiation, focal signet ring histology, and other adverse histologic features such as lymphatic and perineural invasion and high tumor budding.

Clinicopathologic and molecular features of sporadic early-onset colorectal adenocarcinoma: an adenocarcinoma with frequent signet ring cell differentiation, rectal and sigmoid involvement, and adverse morphologic features

Recent literature suggests an increasing incidence of colorectal carcinoma in young patients. We performed a histologic, molecular, and immunophenotypic analysis of patients with sporadic early-onset (≤40 years of age) colorectal carcinoma seen at our institution from the years 2000–2010 and compared these tumors to a cohort of consecutively resected colorectal carcinomas seen in patients >40 years of age. A total of 1160 primary colorectal adenocarcinomas were surgically resected for the years 2000 through 2010. Of these, 75 (6%) were diagnoses in patients ≤40 years of age of which 13 (17%) demonstrated abnormalities in DNA mismatch repair, 4 (5%) were in patients with known germline genetic disorders (two patients with familial adenomatous polyposis, one patient with juvenile polyposis, and one patient with Li-Fraumeni syndrome), and three patients (4%) had long-standing chronic inflammatory bowel disease. The sporadic early-onset colorectal carcinoma group comprised a total of 55 patients (55/1160, 5%) and were compared with a control group comprising 73 consecutively resected colorectal carcinomas with proficient DNA mismatch repair in patients >40 years of age. For the early-onset colorectal carcinoma group, most cases (33/55, 60%) were diagnosed between the age of 35 and 40 years of age. Compared with the control group, the early-onset colorectal carcinoma group was significantly different with respect to tumor location (P<0.007) with 80% (44/55 cases) identified in either the sigmoid colon (24/55, 44%) or rectum (20/55, 36%). Morphologically, early-onset colorectal carcinomas more frequently displayed adverse histologic features compared with the control colorectal carcinoma group such as signet ring cell differentiation (7/55, 13% vs 1/73, 1%, P=0.021), perineural invasion (16/55, 29% vs 8/73, 11%, P=0.009) and venous invasion (12/55, 22% vs 4/73, 6%, P=0.006). A precursor adenomatous lesion was less frequently identified in the early-onset colorectal carcinoma group compared with the control group (19/55, 35% vs 39/73, 53%, P=0.034). Of the early-onset colorectal carcinomas, only 2/45 cases (4%) demonstrated KRAS mutations compared with 11/73 (15%) of the control group colorectal adenocarcinomas harboring KRAS mutations, although this difference did not reach statistical significance (P=0.13). BRAF V600E mutations were not identified in the early-onset colorectal carcinoma group. No difference was identified between the two groups with regard to tumor stage, tumor size, number of lymph node metastases, lymphatic invasion, tumor budding, mucinous histology, or tumor-infiltrating lymphocytes. Both groups had similar recurrence-free (P=0.28) and overall survival (P=0.73). However, patients in the early-onset colorectal carcinoma group more frequently either presented with or developed metastatic disease during their disease course compared with the control colorectal carcinoma group (25/55, 45% vs 18/73, 25%, P=0.014). In addition, 8/55 patients (15%) in the early-onset colorectal carcinoma group developed local recurrence of their tumor while no patients in the control colorectal carcinoma group developed local recurrence (P<0.001), likely due to the increased incidence of rectal carcinoma in the patients with early-onset colorectal carcinoma. Our study demonstrates that colorectal carcinoma is not infrequently diagnosed in patients ≤40 years of age and is not frequently the result of underlying Lynch syndrome or associated with other cancer-predisposing genetic conditions or chronic inflammatory conditions. These tumors have a striking predilection for the distal colon, particularly the sigmoid colon and rectum and are much more likely to demonstrate adverse histologic factors, including signet ring cell differentiation, venous invasion, and perineural invasion.

Coexisting follicular and mantle cell lymphoma with each having an in situ component: A novel, curious, and complex consultation case of coincidental, composite, colonizing lymphoma.

A diagnosis of composite lymphoma is typically prompted by the observation of morphologic discordance. We present a case of a spleen revealing histologic features of follicular lymphoma, without any indication of a second lymphoma. Immunohistochemical stains supported this diagnosis and showed the follicular lymphoma to be BCL2-. However, these studies revealed 2 additional unexpected findings: cyclin D1+ mantle zone cells surrounding neoplastic and reactive follicles (indicative of in situ mantle cell lymphoma) and BCL2-bright, histologically nonneoplastic follicles (indicative of in situ follicular lymphoma). ImmunoFISH and microdissection and polymerase chain reaction analysis documented the clonal nature of the cyclin D1+ mantle zones and illustrated clonal independence from the follicular lymphoma. This case illustrates an uncommon and unusual composite follicular and mantle cell lymphoma, with the follicular lymphoma accompanied by an in situ component, whereas the only manifestation of the mantle cell lymphoma was in situ.

The role of oxidant injury in the pathophysiology of human thalassemias

Abstract The anemia in β-thalassemia major is caused by a combination of hemolysis and ineffective erythropoiesis, with the latter being more important. Studies of the underlying cause of the hemolysis have indicated that oxidant injury to circulating red blood cells (RBCs) was of critical importance, with evidence of oxidant damage to RBC membrane proteins 4.1 and band 3. Therefore, it seemed reasonable that oxidant damage to thalassemic erythroid precursors would cause their accelerated apoptosis and ineffective erythropoiesis. However, direct analysis showed that the apoptotic programs turned on in thalassemics were not those triggered by oxidative damage but were dependent on activation of FAS/FAS-Ligand interaction. Thus, destruction of thalassemic erythroid precursors may involve different mechanisms from those that cause RBC hemolysis.

Next-generation sequencing of acute myeloid leukemia identifies the significance of TP53 , U2AF1 , ASXL1 , and TET2 mutations

We assessed the frequency and clinicopathologic significance of 19 genes currently identified as significantly mutated in myeloid neoplasms, RUNX1, ASXL1, TET2, CEBPA, IDH1, IDH2, DNMT3A, FLT3, NPM1, TP53, NRAS, EZH2, CBL, U2AF1, SF3B1, SRSF2, JAK2, CSF3R, and SETBP1, across 93 cases of acute myeloid leukemia (AML) using capture target enrichment and next-generation sequencing. Of these cases, 79% showed at least one nonsynonymous mutation, and cases of AML with recurrent genetic abnormalities showed a lower frequency of mutations versus AML with myelodysplasia-related changes (P<0.001). Mutational analysis further demonstrated that TP53 mutations are associated with complex karyotype AML, whereas ASXL1 and U2AF1 mutations are associated with AML with myelodysplasia-related changes. Furthermore, U2AF1 mutations were specifically associated with trilineage morphologic dysplasia. Univariate analysis demonstrated that U2AF1 and TP53 mutations are associated with absence of clinical remission, poor overall survival (OS), and poor disease-free survival (DFS; P<0.0001), whereas TET2 and ASXL1 mutations are associated with poor OS (P<0.03). In multivariate analysis, U2AF1 and TP53 mutations retained independent prognostic significance in OS and DFS, respectively. Our results demonstrate unique relationships between mutations in AML, clinicopathologic prognosis, subtype categorization, and morphologic dysplasia.

STAT3 mutations are frequent in CD30+ T-cell lymphomas and T-cell large granular lymphocytic leukemia.

STAT3 mutations are frequent in CD30+ T-cell lymphomas and T-cell large granular lymphocytic leukemia

ETV3-NCOA2 in indeterminate cell histiocytosis: clonal translocation supports sui generis

To the editor: Indeterminate cell histiocytosis (ICH) is a rare and controversial disorder first described by Wood et al[1][1] in 1985. ICH is characterized by a nonepidermotropic histiocytic infiltrate with immunohistochemical features that overlap with Langerhans cells (LCs) and non-LCs of

The frequency of dual TCR-PCR clonality in granulomatous disorders.

Background: A granulomatous infiltrate in association with cutaneous T‐cell lymphoma is uncommon. The diagnosis of mycosis fungoides can be difficult in the setting of an exuberant granulomatous infiltrate that obscures the neoplastic lymphoid infiltrate, thereby mimicking a granulomatous dermatitis. Therefore, the clinical context and supplemental molecular analysis, such as the demonstration of a monoclonal T‐cell population, may assist in diagnosis. Monoclonal T‐cell populations have been reported in association with inflammatory conditions and serve as a diagnostic pitfall. The frequency of T‐cell clonality in association with granulomatous dermatitides has not yet been established.

DNA methylation analysis of ALOX12 and GSTM1 in acute myeloid leukaemia identifies prognostically significant groups

To determine the role of DNA methylation in the progression of acute myeloid leukaemia (AML), we analysed the methylation status of ALOX12, GSTM1, HS3ST2 and FZD9 in 127 AML patients. Aberrant methylation of ALOX12 was associated with the subcategory AML with myelodysplasia‐related changes (P = 0·0439) and specifically with megakaryocytic dysplasia (P = 0·0003). An association between HS3ST2 and AML patients with favourable cytogenetic risk was identified (P = 0·0469). In univariate and multivariate analysis, methylation of GSTM1 was associated with worse overall survival (OS) and disease‐free survival (DFS), with hazard ratios of 2·57 and 1·86, respectively. Furthermore, the significance of methylation of GSTM1 in predicting poor prognosis was maintained within the subcategories of AML not otherwise specified (NOS), AML with intermediate cytogenetic risk and normal karyotype AML. Finally, patients with both GSTM1 and ALOX12 methylated, demonstrated worse outcomes when all AML patients were assessed (OS; P = 0·000411) as well as within AML NOS (DFS; P = 0·0023), AML with intermediate cytogenetic risk (OS; P = 0·0104) and normal karyotype AML (OS; P = 0·00636). This study implicates methylation of specific genes in the classification and prognostication of AML and suggests that the morphological feature of multilineage dysplasia may be a surrogate marker of gene methylation in at least a subset of AML cases.