癌関連脂肪細胞は膵癌のSAA1発現を誘導して膵癌の進展を促進する

Although pancreatic cancer often invades peripancreatic adipose tissue, little information is known about cancer-adipocyte interaction. We first investigated the ability of adipocytes to de-differentiate to cancer-associated adipocytes (CAAs) by co-culturing with pancreatic cancer cells. We then examined the effects of CAA-conditioned medium (CAA-CM) on the malignant characteristics of cancer cells, the mechanism underlying those effects, and their clinical relevance in pancreatic cancer. When 3T3-L1 adipocytes were co-cultured with pancreatic cancer cells (PANC-1) using the Transwell system, adipocytes lost their lipid droplets and changed morphologically to fibroblast-like cells (CAA). Adipocyte-specific marker mRNA levels significantly decreased but those of fibroblast-specific markers appeared, characteristic findings of CAA, as revealed by real-time PCR. When PANC-1 cells were cultured with CAA-CM, significantly higher migration/invasion capability, chemoresistance, and epithelial-mesenchymal transition (EMT) properties were observed compared with control cells. To investigate the mechanism underlying these effects, we performed microarray analysis of PANC-1 cells cultured with CAA-CM and found a 78.5- fold higher expression of SAA1 compared with control cells. When the SAA1 gene in PANC-1 cells was knocked down with SAA1 siRNA, migration/invasion capability, chemoresistance, and EMT properties were significantly attenuated compared with control cells. Immunohistochemical analysis on human pancreatic cancer tissues revealed positive SAA1 expression in 46/61 (75.4%). Overall survival in the SAA1-positive group was significantly shorter than in the SAA1-negative group (P = .013). In conclusion, we demonstrated that pancreatic cancer cells induced de-differentiation in adipocytes toward CAA, and that CAA promoted malignant characteristics of pancreatic cancer via SAA1 expression, suggesting that SAA1 is a novel therapeutic target in pancreatic cancer

Augmentation of Reverse Transcription by Integrase through an Interaction with Host Factor, SIP1/Gemin2 Is Critical for HIV-1 Infection

There has been accumulating evidence for the involvement of retroviral integrase (IN) in the reverse transcription of viral RNA. We previously identified a host factor, survival motor neuron-interacting protein 1 (SIP1/Gemin2) that binds to human immunodeficiency virus type 1 (HIV-1) IN and supports HIV-1 infection apparently at reverse transcription step. Here, we demonstrated that HIV-1 IN together with SIP1 augments reverse transcriptase (RT) activity by enhancing the assembly of RT on viral RNA in vitro. Synthetic peptides corresponding to the binding motifs within IN that inhibited the IN-SIP1 interaction abrogated reverse transcription in vitro and in vivo. Furthermore, knockdown of SIP1 reduced intracellular stability and multimer formation of IN through proteasome-mediated degradation machinery. Taken together, SIP1 appears to stabilize functional multimer forms of IN, thereby promoting the assembly of IN and RT on viral RNA to allow efficient reverse transcription, which is a prerequisite for efficient HIV-1 infection

Expression of Tim-1 in primary CNS lymphoma

Primary central nervous system lymphoma (PCNSL) is a distinct subtype of extranodal lymphoma with aggressive clinical course and poor outcome. As increased IL-10/IL-6 ratio is recognized in the cerebrospinal fluid (CSF) of PCNSL patients, we hypothesized that PCNSL might originate from a population of B cells with high IL-10-producing capacity, an equivalent of "regulatory B cells" in mice. We intended in this study to clarify whether Tim-1, a molecule known as a marker for regulatory B cells in mice, is expressed in PCNSL. By immunohistochemical analysis, Tim-1 was shown to be positive in as high as 54.2% of PCNSL (26 of 58 samples), while it was positive in 19.1% of systemic diffuse large B-cell lymphoma (DLBCL) samples (17 of 89 samples; P < 0.001). Tim-1 expression positively correlated with IL-10 expression in PCNSL (Cramer's V = 0.55, P < 0.001), and forced expression of Tim-1 in a PCNSL cell line resulted in increased IL-10 secretion, suggesting that Tim-1 is functionally linked with IL-10 production in PCNSL. Moreover, soluble Tim-1 was detectable in the CSF of PCNSL patients, and was suggested to parallel disease activity. In summary, PCNSL is characterized by frequent Tim-1 expression, and its soluble form in CSF may become a useful biomarker for PCNSL

Assessment of postoperative common bile duct stones after endoscopic extraction and subsequent cholecystectomy

Background Common bile duct stones (CBDSs) occasionally cause serious diseases, and endoscopic extraction is the standard procedure for CBDS. To prevent biliary complications, cholecystectomy is recommended for patients who present with gallbladder (GB) stones after endoscopic CBDS extraction. However, CBDS can occasionally recur. To date, the occurrence of CBDS after endoscopic CBDS extraction and subsequent cholecystectomy is not fully understood. Hence, the current study aimed to evaluate the incidence of postoperative CBDSs. Methods This retrospective observational study included consecutive patients who underwent postoperative endoscopic retrograde cholangiography after endoscopic CBDS extraction and subsequent cholecystectomy between April 2012 and June 2021 at our institution. After endoscopic CBDS extraction, a biliary plastic stent was inserted to prevent obstructive cholangitis. Endoscopic retrograde cholangiography was performed to evaluate postoperative CBDSs after cholecystectomy until hospital discharge. The outcomes were the incidence of postoperative CBDSs and CBDSs/sludge. Moreover, the predictive factors for postoperative CBDSs were evaluated via univariate and multivariate analyses. Results Of eligible 204 patients, 52 patients (25.5%) presented with postoperative CBDSs. The incidence rate of CBDS/sludge was 36.8% (n = 75). Based on the univariate analysis, the significant predictive factors for postoperative CBDSs were >= 6 CBDSs, presence of cystic duct stones, and >= 10 GB stones (P = 6 CBDSs (odds ratio = 6.65, P = 10 GB stones (odds ratio = 2.55, P = 0.01) were independent predictive factors for postoperative CBDSs. Conclusions The incidence of postoperative CBDS was relatively high. Hence, patients with predictive factors for postoperative CBDS must undergo imaging tests or additional endoscopic procedure after cholecystectomy