ObjectivesTo determine clinical and genetic features of individuals with relapsing polychondritis (RP) likely caused by pathogenic somatic variants in ubiquitin-like modifier activating enzyme 1 (UBA1).MethodsFourteen patients with RP who met the Damiani and Levine criteria were recruited (12 men, 2 women; median onset age (IQR) 72.1 years (67.1–78.0)). Sanger sequencing of UBA1 was performed using genomic DNA from peripheral blood leukocytes or bone marrow tissue. Droplet digital PCR (ddPCR) and peptide nucleic acid (PNA)-clamping PCR were used to detect low-prevalence somatic variants. Clinical features of the patients were investigated retrospectively.ResultsUBA1 was examined in 13 of the 14 patients; 73% (8/11) of the male patients had somatic UBA1 variants (c.121A>C, c.121A>G or c.122T>C resulting in p.Met41Leu, p.Met41Val or p.Met41Thr, respectively). All the variant-positive patients had systemic symptoms, including a significantly high prevalence of skin lesions. ddPCR detected low prevalence (0.14%) of somatic variant (c.121A>C) in one female patient, which was subsequently confirmed by PNA-clamping PCR.ConclusionsGenetic screening for pathogenic UBA1 variants should be considered in patients with RP, especially male patients with skin lesions. The somatic variant in UBA1 in the female patient is the first to be reported.

Inflammatory myofibroblastic tumor is a rare tumor deriving from mesenchymal tissue. Approximately 50% of inflammatory myofibroblastic tumors harbor an anaplastic lymphoma kinase fusion gene. Pulmonary inflammatory myofibroblastic tumors harboring tropomyosin3-anaplastic lymphoma kinase or protein tyrosine phosphatase receptor-type F polypeptideinteracting protein-binding protein 1-anaplastic lymphoma kinase have been reported previously. However, it has not been reported that inflammatory myofibroblastic tumors harbor echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene which is considered to be very specific to lung cancers. A few tumors harboring echinoderm microtubuleassociated protein-like 4-anaplastic lymphoma kinase fusion gene other than lung cancers have been reported and the tumors were all carcinomas. A 67-year-old man had been followed up for a benign tumor for approximately 3 years before the tumor demonstrated malignant transformation. Lobectomy and autopsy revealed that an inflammatory myofibroblastic tumor harboring echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene had transformed into an undifferentiated sarcoma. This case suggests that echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion is an oncogenic event in not only carcinomas but also sarcomas originating from stromal cells.

Background: PAR-3 is one of the PAR proteins, previously named ASIP, which are indispensable for the establishment of cell polarity in the embryo as well as differentiated epithelial cells. In mammalian epithelial cells, it forms a ternary complex with aPKC and PAR-6, and is localized to the tight junction that has been suggested as being important for creating cell polarity.

Genetically engineered mice (GEM) are the gold standard for cancer modeling. However, strict recapitulation of stepwise carcinogenesis from a single tumor-initiating epithelial cell among genetically intact cells in adults is not feasible with the currently available techniques using GEM. In previous studies, we partially overcame this challenge by physically isolating organs from adult animals, followed by genetic engineering in organoids and subcutaneous inoculation in nude mice. Despite the establishment of suitable ex vivo carcinogenesis models for diverse tissues, tumor development remained ectopic and occurred under immunodeficient conditions. Further refinement was, therefore, necessary to establish ideal models. Given the poor prognosis and few models owing to the lack of gall bladder (GB)-specific Cre strain, we assumed that the development of authentic models would considerably benefit GB cancer research. Here, we established a novel model using GB organoids with mutant Kras and Trp53 loss generated in vitro by lentiviral Cre transduction and CRISPR/Cas9 gene editing, respectively. Organoid-derived subcutaneous tumor fragments were sutured to the outer surface of the GB in syngeneic mice, which developed orthotopic tumors that resembled human GB cancer in histological and transcriptional features. This model revealed the infiltration of similar subsets of immune cells in both subcutaneous and orthotopic tumors, confirming the appropriate immune environment during carcinogenesis. In addition, we accurately validated the in vivo efficacy of gemcitabine, a common therapeutic agent for GB cancer, in large cohorts. Taken together, this model may serve as a promising avatar of patients with GB cancer in drug discovery and precision medicine.

Reported herein is a case of hepatocellular carcinoma (HCC) occurring in a 25-year-old Japanese man who was diagnosed with Crohn's disease (CD) at 14 years of age; treatment included predonisolone, azathioprine, and infliximab. The tumor was located in right upper lobe and the size was 8 cm in diameter; histology was poorly differentiated HCC with pleomorphic cellular changes. Adjacent normal liver showed no evidence of cirrhosis or viral hepatitis. Until now, only six cases of HCC arising in patients with CD have been reported in the English-language literature. Most of these patients had early onset of CD and HCC: none had cirrhosis or virus hepatitis. Most patients had a long disease history of CD and were being medicated with several immunosuppressive agents. Some factors associated with CD might indirectly or directly be related to the development of HCC in CD patients, although the possibility that these HCC occurred coincidentally in CD patients, including the present patient, cannot be ruled out. Accumulation of cases is necessary to evaluate the relationship between CD and HCC precisely.

Programmed cell death-1 (PD-1) is involved in one of the inhibitory pathways of the B7-cluster of differentiation (CD) 28 family; this pathway is known to be involved in the attenuation of T-cell responses and promotion of T-cell tolerance. PD-1 is known to negatively regulate T-cell receptor-mediated proliferation and cytokine production, lead to alternation in the tumor microenvironment. Although several studies have shown that high levels of PD-1-positive cells in follicular lymphoma (FL) patients influence their prognosis, those studies included patients treated without rituximab, and the prognostic impact of PD-1 positivity in the rituximab era (R-era) has not yet been elucidated. We retrospectively studied 82 patients with FL uniformly treated with standard R-CHOP therapy at six institutions between 2001 and 2009 (median follow-up for survivors: 55 months). We also collected and examined biopsy specimens for diagnosis with respect to PD-1 positivity. The PD-1 positivity was significantly higher in male patients and patients with high beta-2 microglobulin (B2M ≥ 3.0) (P = 0.03 and 0.003, respectively). Three-year progression free survival (PFS) and overall survival (OS) were 60% and 86%, respectively. By univariate analysis, elevated LDH (P = 0.07) worsened PFS. Male gender (P = 0.03), high FLIPI score (P = 0.05), and high B2M levels (P = 0.08) worsened OS. Multivariate analysis detected no significant prognostic factors, including PD-1 positivity. However, in male subgroup, high levels of PD-1-positive cells were found to be a prognostic factor for PFS. Addition of rituximab might have altered the prognostic impact of PD-1-positive cells.

Succinate dehydrogenase-deficient renal cell carcinoma (SDH-deficient RCC) is a newly introduced histological type of RCC, which is caused by loss of subunit genes of SDH. It is known to frequently demonstrate familial occurrence and be frequently associated with gastrointestinal stromal tumors and paraganglioma. To date, only 53 cases have been reported. Here, we present an additional case of SDH-deficient RCC occurring in a 40-year-old female. The tumor was histologically biphasic, consisting of tubular and solid architectures. The tumor cells possessed oval nuclei with small nucleoli, and an eosinophilic granular cytoplasm with occasional vacuoles. These cells completely lost the immunohistochemical expression of B subunit of SDH (SDHB). Consequently, the tumor was diagnosed as SDHB-deficient RCC. We identified a novel germ line mutation of the SDHB gene, and also confirmed a hemizygous deletion of the wild-type allele in the tumor cells. To define the pathological characteristics of SDH-deficient RCC, precise diagnosis and accumulation of more cases are required.

Acute myeloid leukemia (AML) or myelodysplastic syndromes (MDS) with both inv(3)(q21q26.2)/t(3;3)(q21;q26.2) and monosomy 7 defines an extremely aggressive myeloid cancer whose molecular pathogenesis and optimal therapeutic strategy still remain unclear. We established a new MDS/AML cell line, YCU-AML1, and its patient-derived xenograft (PDX) model from a high-risk MDS patient who later transformed into AML harboring both t(3;3)(q21;q26.2) and monosomy 7. YCU-AML1 cells propagated in co-culture system with stromal cells in granulocyte macrophage colony-stimulating factor (GM-CSF)-dependent manner. CD34+ bone marrow cells derived from our PDX model showed high EVI1 and low GATA2 expression. Moreover, mutational profile of our MDS/AML model was consistent with recently published mutational spectrum of myeloid malignancies with inv(3)/t(3;3). These data suggest that YCU-AML1 cells and its MDS/AML model strongly mimics a high-risk human myeloid cancer with inv(3)(q21q26.2)/t(3;3)(q21;q26.2) and monosomy 7 in terms of both clinical phenotype and molecular basis. We believe our model can be used as a feasible tool to further explore molecular pathogenesis and novel treatment strategy of high-risk MDS/AML with t(3;3)(q21;q26.2) and monosomy 7.