Background:We searched for a viral aetiology for non-small cell lung cancer (NSCLC), focusing on Merkel cell polyomavirus (MCPyV).Methods:We analysed 112 Japanese cases of NSCLC for the presence of the MCPyV genome and the expressions of RNA transcripts and MCPyV-encoded antigen. We also conducted the first analysis of the molecular features of MCPyV in lung cancers.Results:PCR revealed that 9 out of 32 squamous cell carcinomas (SCCs), 9 out of 45 adenocarcinomas (ACs), 1 out of 32 large-cell carcinomas, and 1 out of 3 pleomorphic carcinomas were positive for MCPyV DNA. Some MCPyV DNA-positive cancers expressed large T antigen (LT) RNA transcripts. Immunohistochemistry showed that MCPyV LT antigen was expressed in the tumour cells. The viral integration sites were identified in one SCC and one AC. One had both episomal and integrated/truncated forms. The other carried an integrated MCPyV genome with frameshift mutations in the LT gene.Conclusion:We have demonstrated the expression of a viral oncoprotein, the presence of integrated MCPyV, and a truncated LT gene with a preserved retinoblastoma tumour-suppressor protein-binding domain in NSCLCs. Although the viral prevalence was low, the tumour-specific molecular signatures support the possibility that MCPyV is partly associated with the pathogenesis of NSCLC in a subset of patients.

A link between hyperthyroidism and pulmonary hypertension has been reported, but the underlying mechanisms of these two conditions have not been clearly identified. The aim of this study was to determine the clinical correlates of pulmonary hypertension in patients with Graves’ disease. Among 50 consecutive patients with Graves’ disease referred for echocardiography, 18 patients (36 %) had pulmonary hypertension measured by continuous-wave Doppler echocardiography (pulmonary artery systolic pressure >35 mmHg). The patients with pulmonary hypertension had significantly higher pulmonary vascular resistance (PVR), cardiac output and thyroid-stimulating hormone receptor antibody (TRAb) compared to those without (p < 0.001, p = 0.028 and p < 0.001, respectively). Pulmonary artery systolic pressure had a good correlation with TRAb (r = 0.74, p < 0.001), but was not related to free T4 (r = 0.12, p = 0.419) and free T3 (r = 0.22, p = 0.126). To determine the important variables present in patients with Graves’ disease that may be related to pulmonary artery systolic pressure, 4 variables (PVR, cardiac output, TRAb and free T3) were used in the multivariate analysis. In addition to PVR (standard regression coefficient = 0.831, p < 0.001) and cardiac output (standard regression coefficient = 0.592, p < 0.001), TRAb (standard regression coefficient = 0.178, p < 0.001) emerged as a significant variable related to pulmonary artery systolic pressure. Thus, in addition to the effect of thyroid hormone on the cardiovascular system, autoimmune-mediated pulmonary vascular remodeling may play a role in Graves’ disease-linked elevated pulmonary artery systolic pressure.

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Squamous cell lung carcinoma cells obtained from a patient who presented with leukocytosis and hypercalcemia were transplanted into nude mice anda serially transplantable cell line, OKa‐N‐1, was established. The nude mice transplanted with OKa‐N‐1 cells displayed leukocytosis and hypercalcemia. Serum levels of granulocyte colony‐stimulating factor (G‐CSF) and parathyroid hormone‐related protein (PTHrP) were both elevated in these mice. In vitro cultivation of this tumor cell line gave rise to a clonal cell line, OKa‐C‐1. Nude mice transplanted with the OKa‐C‐1 cell line also showed leukocytosis and hypercalcemia with high serum G‐CSF and PTHrP levels. The culture supernatant of OKa‐C‐1 contained high levels of G‐CSF and PTHrP. Immunohistochemical studies showed the expression of PTHrP in OKa‐C‐1 cells. Reverse transcription polymerase chain reaction revealed the presence of G‐CSF and PTHrP mRNA in this cell line. Dexamethasone treatment inhibited the transcription of G‐CSF and PTHrP genes. This new human squamous carcinoma cell line, OKa‐C‐1, would be useful for studying the mechanism of simultaneous production of G‐CSF and PTHrP and their control in cancer patients with leukocytosis and hypercalcemia.

BackgroundChronic lymphocytic leukemia (CLL) is the rarest adult leukemia in Japan, whereas it is the most common leukemia in the Western world. Recent studies from the United States and Germany suggest a possible etiological association between Merkel cell polyomavirus (MCPyV) and CLL, although no data have been reported from Eastern countries. To increase the volume of relevant data, this study investigated the prevalence and DNA loads of MCPyV and human polyomavirus 9 (HPyV9), another lymphotropic polyomavirus, in Japanese CLL cases.FindingsWe found that 9/27 CLL cases (33.3 %) were positive for MCPyV using quantitative real-time polymerase chain reaction analysis. The viral DNA loads ranged from 0.000017 to 0.0012 copies per cell. All cases were negative for HPyV9. One MCPyV-positive CLL case was evaluated by mutational analysis of the large T (LT) gene, which indicated the presence of wild-type MCPyV without a nucleotide deletion. DNA sequence analysis of the entire small T (ST) gene and the partial LT gene revealed that a Japanese MCPyV isolate, designated CLL-JK, had two nucleotide gaps when compared with the reference sequence of the North American isolate MCC350.ConclusionsThis study provides the first evidence that MCPyV is present in a subset of Japanese CLL cases with low viral DNA loads. MCPyV and HPyV9 are unlikely to contribute directly to the development of CLL in the majority of Japanese cases. MCPyV isolated from the Japanese CLL cases may constitute an Asian group and its pathogenicity needs to be clarified in future studies.