Signet‐ring cell/histiocytoid carcinoma in the axilla: A case report with genetic analysis using next‐generation sequencing

Signet‐ring cell/histiocytoid carcinoma (SRCHC) is a very rare skin appendage cancer, with an extremely rare occurrence in the axilla. This study describes the 11th case of SRCHC occurring in the axilla and reports the first gene alteration analysis performed for SRCHC. An 85‐year‐old Japanese male presented with a tumor in the left axilla. Biopsy of the axilla nodule demonstrated diffuse proliferation of histiocytoid neoplastic cells and signet‐ring cells in the dermis and subcutis. Immunohistochemistry revealed loss of E‐cadherin expression in these neoplastic cells. Accordingly, SRCHC of the axilla was diagnosed. Genetic analysis using next‐generation sequencing demonstrated missense mutation of PIK3CA (c1633G>A, pGlu545Lys) and no CDH1 gene mutation.SRCHC of the axilla is considered equivalent to a histiocytoid variant of invasive lobular breast carcinoma. The present SRCHC case demonstrated a pathogenic PIK3CA mutation, which is observed in invasive lobular carcinoma. Additional large case studies are required to clarify the clinicopathological features and gene alterations in SRCHC of the axilla.     

Human native endocarditis caused by Streptococcus canis—a case report

We report a very rare case of Streptococcus canis native infective endocarditis in a 73‐year‐old woman living in close contact with her dog. Her echocardiography showed large calcifications in the mitral annulus, massive regurgitation below the posterior leaflet, and adjacent vegetation. Blood culture was positive for Streptococcus Lancefield group G. A coronary artery bypass and mitral valve replacement had to be done. Streptococcus canis was detected in a heart valve using a broad range PCR followed by 16S rRNA and confirmed by tuf gene sequencing, while tissue culture remained negative. The patient was not bitten by her dog nor did she have comorbidities or skin ulcers. She fully recovered.     

TP53 and therapy-related myeloid neoplasms

Therapy-related myeloid neoplasms (t-MNs) are the most serious late complications in patients treated with traditional cytotoxic chemotherapy and/or radiation. T-MNs are aggressive and chemorefractory hematologic malignancies, with a median survival of less than 6 months. TP53 mutations are highly enriched in t-MN patients, though the mechanism for this selective enrichment has only come to light over the past several years. In this review, we discuss the history and function of p53, and the role of TP53 mutations in the origin and progression of t-MNs. Emerging data has begun to elucidate who may be at highest risk of developing t-MNs, which ideally will enable us to develop preventative strategies for this devastating disease. As t-MNs may not be avoidable, novel therapies are urgently needed for this patient group and are underway as exemplified by recent investigation in restoring wild-type p53 function as well as directly targeting TP53 mutant variants. With better prevention and treatment, outcomes will hopefully begin to improve in the near future.     

Germline gain-of-function MMP11 variant results in an aggressive form of colorectal cancer

Matrix metalloproteinase-11 (MMP11) is an enzyme with proteolytic activity against matrix and nonmatrix proteins. Although most MMPs are secreted as inactive proenzymes and are later activated extracellularly, MMP11 is activated intracellularly by furin within the constitutive secretory pathway. It is a key factor in physiological tissue remodeling and its alteration may play an important role in the progression of epithelial malignancies and other diseases. TCGA colon and colorectal adenocarcinoma data showed that upregulation of MMP11 expression correlates with tumorigenesis and malignancy. Here, we provide evidence that a germline variant in the MMP11 gene (NM_005940: c.232C>T; p.(Pro78Ser)), identified by whole exome sequencing, can increase the tumorigenic properties of colorectal cancer (CRC) cells. P78S is located in the prodomain region, which is responsible for blocking MMP11's protease activity. This variant was detected in the proband and all the cancer-affected family members analyzed, while it was not detected in healthy relatives. In silico analyses predict that P78S could have an impact on the activation of the enzyme. Furthermore, our in vitro analyses show that the expression of P78S in HCT116 cells increases tumor cell invasion and proliferation. In summary, our results show that this variant could modify the structure of the MMP11 prodomain, producing a premature or uncontrolled activation of the enzyme that may contribute to an early CRC onset in these patients. The study of this gene in other CRC cases will provide further information about its role in CRC development, which might improve patient treatment in the future.     

Correlación genotipo-fenotipo en miocardiopatía hipertrófica: un estudio multicéntrico en Portugal y España sobre la variante p.Arg21Leu de TPM1

Introduction and objectivesTPM1 is one of the main hypertrophic cardiomyopathy (HCM) genes. Clinical information on carriers is relatively scarce, limiting the interpretation of genetic findings in individual patients. Our aim was to establish genotype-phenotype correlations of the TPM1 p.Arg21Leu variant in a serie of pedigrees.MethodsTPM1 was evaluated by next-generation sequencing in 10 561 unrelated probands with inherited heart diseases. Familial genetic screening was performed by the Sanger method. We analyzed TPM1 p.Arg21Leu pedigrees for cosegregation, clinical characteristics, and outcomes. We also estimated the geographical distribution of the carrier families in Portugal and Spain.ResultsThe TPM1 p.Arg21Leu variant was identified in 25/4099 (0.61%) HCM-cases, and was absent in 6462 control individuals with other inherited cardiac phenotypes (P < .0001). In total, 83 carriers (31 probands) were identified. The combined LOD score for familial cosegregation was 3.95. The cumulative probability of diagnosis in carriers was 50% at the age of 50 years for males, and was 25% in female carriers. At the age of 70 years, 17% of males and 46% of female carriers were unaffected. Mean maximal left ventricular wall thickness was 21.4 ± 7.65 mm. Calculated HCM sudden death risk was low in 34 carriers (77.5%), intermediated in 8 (18%), and high in only 2 (4.5%). Survival free of cardiovascular death or heart transplant was 87.5% at 50 years. Six percent of carriers were homozygous and 18% had an additional variant. Family origin was concentrated in Galicia, Extremadura, and northern Portugal, suggesting a founder effect.ConclusionsTPM1 p.Arg21Leu is a pathogenic HCM variant associated with late-onset/incomplete penetrance and a generally favorable prognosis.     

Correlation analysis of intestinal flora and pathological process of type 2 diabetes mellitus

ObjectiveTo observe the relationship between the different stages of type 2 diabetes mellitus (T2DM) and the intestinal flora and verify its underlying mechanism.MethodsT2DM rats were generated by high-fat diet (HFD) combined with intraperitoneal streptozotocin (STZ) injection. The rats were divided into four groups: the control group (fed with normal feed for 1 month), the HFD group (fed with HFD for 1 month), the T2DM group (HFD combined with STZ and blood glucose ≥11.1 mM), and the unformed T2DM model (Un-mod) group (HFD combined with STZ and blood glucose <11.1 mM). Feces were collected, and bacterial communities in the fecal samples were analyzed by 16S rRNA gene sequencing. The content of short-chain fatty acids (SCFAs) in feces was measured by gas chromatography. Western blot and quantitative real-time polymerase chain reaction were used to detect the expression of G protein-coupled receptor 41 (GPR41) and GPR43.ResultsAt different stages of T2DM, the intestinal flora and SCFAs content of rats were significantly decreased (all P < .05). Our results indicated that g__Prevotella had a significant negative correlation, and g__Ruminococcus_torques_group and g__lachnoclastic had a significant positive correlation with blood glucose. The content of SCFAs, in particular acetate and butyrate, in rat feces of different stages of T2DM were significantly reduced, as well as GPR41 and GPR43 expression. The results in the Un-mod group were similar to the T2DM group, and the expression of GPR41 and GPR43 proteins were significantly higher than those in the T2DM group (both P < .001).ConclusionThe intestinal flora–SCFAs–GPR41/GPR43 network may be important in the development of T2DM. Decreasing blood glucose levels by regulating the intestinal flora may become a new therapeutic strategy for T2DM, which has very important clinical and social values.     

Tfh-cell-derived interleukin 21 sustains effector CD8+ T cell responses during chronic viral infection

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