Abstract: Background Cisplatin (CDDP) is extensively used for esophageal adenocarcinoma (EAC) chemotherapy, while cisplatin resistance is getting worse microRNA-181a-5p (miR-181a-5p) has been reported to play an important role in various human cancers However, the effect and underlying mechanism of miR-181a-5p in cisplatin resistance of EAC remain unclear Methods Cisplatin-resistant EAC cells OE19/CDDP and parental sensitive OE19 cells were applied for experiments in vitro The expressions of miR-181a-5p and CBLB were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot The cisplatin resistance of cells was expressed by cell viability, IC50 and apoptosis rate by using CCK-8 assay or flow cytometry The interaction between miR-181a-5p and CBLB was evaluated by luciferase reporter assay and RIP assay In vivo experiments were conducted via the murine xenograft model Results miR-181a-5p was highly expressed while CBLB was lowly expressed in OE19 cell lines compared with OE19/CDDP cells In cisplatin-resistant OE19/CDDP cells, miR-181a-5p up-regulation or CBLB knockdown inhibited cell viability and inducted apoptosis In cisplatin-sensitive OE19 cells, miR-181a-5p inhibition or CBLB overexpression promoted cell viability and suppressed apoptosis CBLB was confirmed to be a target of miR-181a-5p, and rescue assay showed CBLB overexpression reversed the suppression of OE19/CDDP cell viability induced by miR-181a-5p up-regulation, and its down-regulation attenuated miR-181a-5p-inhibition-mediated enhancement of OE19 cell viability In addition, miR-181a-5p up-regulation enhanced the cytotoxicity of cisplatin in EAC in vivo Conclusion miR-181a-5p enhanced the sensitivity of cells to cisplatin in EAC by targeting CBLB, indicating a promising sensitizer of cisplatin therapy in clinical esophageal cancer

Abstract: Cancer is one of the leading causes of mortality worldwide. Breast cancer is the most frequent cancer in women, and in recent years it has become a serious public health problem in Colombia. The development of large-scale omic techniques allows simultaneous analysis of all active genes in tumor cells versus normal cells, providing new ways to discover the drivers of malignant transformations. Whole exome sequencing (WES) was obtained to provide a deep view of the mutational genomic profile in a set of cancer samples from Southwest Colombian women. WES was performed on 52 tumor samples from patients diagnosed with invasive breast cancer, which in most cases (33/52) were ductal luminal breast carcinomas (IDC-LM-BRCA). Global variant call was calculated, and six different algorithms were applied to filter out false positives and identify pathogenic variants. To compare and expand the somatic tumor variants found in the Colombian cohort, exome mutations and genome-wide expression alterations were detected in a larger set of tumor samples of the same breast cancer subtype from TCGA (that included DNA-seq and RNA-seq data). Genes with significant changes in both the mutational and expression profiles were identified, providing a set of genes and mutations associated with the etiology of ductal luminal breast cancer. This set included 19 single mutations identified as tumor driver mutations in 17 genes. Some of the genes (ATM, ERBB3, ESR1, TP53) are well-known cancer genes, while others (CBLB, PRPF8) presented driver mutations that had not been reported before. In the case of the CBLB gene, several mutations were identified in TCGA IDC-LM-BRCA samples associated with overexpression of this gene and repression of tumor suppressive activity of TGF-β pathway.

Abstract: The transcription factors EBF1 and PAX5 are frequently mutated in B cell acute lymphoblastic leukemia (B-ALL). We demonstrate that Pax5+/- x Ebf1+/- compound heterozygous mice develop highly penetrant leukemia. Similar results were seen in Pax5+/- x Ikzf1+/- and Ebf1+/- x Ikzf1+/- mice for B-ALL, or in Tcf7+/- x Ikzf1+/- mice for T cell leukemia. To identify genetic defects that cooperate with Pax5 and Ebf1 compound heterozygosity to initiate leukemia, we performed a Sleeping Beauty (SB) transposon screen that identified cooperating partners including gain-of-function mutations in Stat5 (~65%) and Jak1(~68%), or loss-of-function mutations in Cblb (61%) and Myb (32%). These findings underscore the role of JAK/STAT5 signaling in B cell transformation and demonstrate unexpected roles for loss-of-function mutations in Cblb and Myb in leukemic transformation. RNA-Seq studies demonstrated upregulation of a PDK1>SGK3>MYC pathway; treatment of Pax5+/- x Ebf1+/- leukemia cells with PDK1 inhibitors blocked proliferation in vitro. Finally, we identified conserved transcriptional variation in a subset of genes between human leukemias and our mouse B-ALL models. Thus, compound haploinsufficiency for B cell transcription factors likely plays a critical role in transformation of human B cells and suggest that PDK1 inhibitors may be effective for treating patients with such defects.

Abstract: Background Multiple symmetric lipomatosis (MSL) is a rare disease showing chronic progression of multiple, symmetrical, and non-encapsulated subcutaneous lipoma. The cause of the disease remains unknown. Patients and methods This study reported and summarized 13 sporadic cases of Type I MSL patients in terms of histopathology and cellular and molecular biology and assessed the CBLB c.197A>T mutation in the IRS1-PI3K-Akt pathway. Results The clinical data showed that these 13 Type I patients were all male with a mean age of 57.0 ± 6.6 years old and consumed alcohol heavily. The laboratory tests revealed that most of the patients had hyperuricemia, diabetes, hyperinsulinemia, or insulin resistance; however, their blood lipid levels were close to a normal range. The imaging data exhibited lipomas that only occurred subcutaneously but not viscerally, ie, Types Ia (15.4%), Ib (30.8%), and Ic (53.8%). The molecular analyses of adipocytes of isoprenaline stimulated human adipose tissue-derived mesenchymal stromal cells (hADSCs) isolated from the adipose tissue lipoma-like masses (ATLLM) demonstrated that these adipocytes did not express UCP-1. The Cbl proto-oncogene B (CBLB), an E3 ubiquitin-protein ligase, was associated with insulin resistance and obesity and was mutated (ie, CBLB c.197A>T) in four MSL patients after the whole genome and Sanger sequencing of the blood samples. Furthermore, the CBLB c.197A>T mutation induced hADSC resistance to insulin by inactivation of the IRS-1-PI3K-AKT pathway. Conclusion This study analyzed clinical, histopathological, and cellular and molecular biological characterizations of 13 Type I MSL patients and identified the CBLB c.197A>T heterozygous mutation that could be responsible for MSL metabolic dysfunction or even MSL development.

Abstract: OBJECTIVE The purpose of this study was to investigate the effect of Casitas b-lineage lymphoma b (Cblb) on the regulation of T follicular helper (Tfh) in the development of lupus nephritis. MATERIALS AND METHODS The Tfh (CD4+CXCR5+PD-1+) cells in peripheral blood were analyzed by flow cytometry. Forty mice were divided into 4 groups (10/group), WT, lpr, Cblb-/- and lpr.Cblb-/-. Urine protein, serum creatinine, blood urea nitrogen (BUN), dsDNA, and antinuclear antibody (ANA) titer of mice were monitored once every four weeks. Peripheral blood mononuclear cells (PBMCs) from mice were collected to assess circulating Tfh. The expressions of Cblb in Tfh cells were regulated by transfecting siRNA and overexpression plasmid approach in vitro. RESULTS The patients with lupus nephritis (LN) had abnormal renal clinical manifestations compared with healthy volunteers. The peripheral Tfh cells were increased and the expression of Cblb were downregulated in patients with LN (p<0.05). Both lpr mice and lpr.Cblb-/- mice had LN symptoms. LN symptoms were more serious in lpr.Cblb-/- mice compared with that in lpr mice (p<0.05). The number of Tfh cells in peripheral blood from lpr.Cblb-/- mice was significantly higher than that from lpr mice (p<0.05). Overexpression of Cblb in Tfh cells led to reduction of IgG expression, while the knockdown of Cblb in Tfh cells was accompanied by increased expression of immunoglobulin (IgG) (p<0.05). CONCLUSIONS Cblb showed a negative regulatory effect on Tfh. The deletion of Cblb may be a key factor in progression of renal injury.

Abstract: Non-Tuberculous Mycobacteria (NTM) are ubiquitous in nature, present in soil and water, and cause primary leading to disseminated infections in immunocompromised individuals. NTM infections are surging in recent years due to an increase in an immune-suppressed population, medical interventions, and patients with underlying lung diseases. Host regulators of innate immune responses, frontiers for controlling infections and dissemination, are poorly defined during NTM infections. Here, we describe the role of CBLB, an E3-ubiquitin ligase, for innate immune responses and disease progression in a mouse model of NTM infection under compromised T-cell immunity. We found that CBLB thwarted NTM growth and dissemination in a time- and infection route- dependent manner. Mechanistically, we uncovered defects in many innate immune cells in the absence of Cblb, including poor responses of NK cells, inflammatory monocytes, and conventional dendritic cells. Strikingly, Cblb-deficient macrophages were competent to control NTM growth in vitro. Histopathology suggested the lack of early formation of granulomatous inflammation in the absence of CBLB. Collectively, CBLB is essential to mount productive innate immune responses and help prevent the dissemination during an NTM infection under T-cell deficiency.

Abstract: E3 ubiquitin ligase Cbl-b is involved in the maintenance of a balance between immunity and tolerance. Mice lacking Cbl-b are highly susceptible to experimental autoimmune encephalomyelitis (EAE), a Th17-mediated autoimmune disease. However, how Cbl-b regulates Th17 cell responses remains unclear. In this study, utilizing adoptive transfer and cell type-specific Cblb knockout strains we show that Cbl-b expression in macrophages, but not T cells or dendritic cells (DCs), restrains the generation of pathogenic Th17 cells and the development of EAE. Cbl-b inhibits the production of IL-6 by macrophages induced by the signaling derived from C-type lectin receptors, which directs T cells to generate pathogenic Th17 cells. Therefore, our data are the first to unveil a previously unappreciated function for Cbl-b in the regulation of pathogenic Th17 responses.