Proteomic Profiling of BRAFV600E Mutant Colon Cancer Cells Reveals the Involvement of Nucleophosmin/c-Myc Axis in Modulating the Response and Resistance to BRAF Inhibition by Vemurafenib.

BRAFV600E mutations are found in approximately 10% of colorectal cancer patients and are associated with worse prognosis and poor outcomes with systemic therapies. The aim of this study was to identify novel druggable features of BRAFV600E-mutated colon cancer (CC) cells associated with the response and resistance to BRAFV600E inhibitor vemurafenib. Towards this aim, we carried out global proteomic profiling of BRAFV600E mutant vs. KRAS mutant/BRAF wild-type and double wild-type KRAS/BRAF CC cells followed by bioinformatics analyses. Validation of selected proteomic features was performed by immunohistochemistry and in silico using the TCGA database. We reveal an increased abundance and activity of nucleophosmin (NPM1) in BRAFV600E-mutated CC in vitro, in silico and in tumor tissues from colon adenocarcinoma patients and demonstrate the roles of NPM1 and its interaction partner c-Myc in conveying the resistance to vemurafenib. Pharmacological inhibition of NPM1 effectively restored the sensitivity of vemurafenib-resistant BRAF-mutated CC cells by down-regulating c-Myc expression and activity and consequently suppressing its transcriptional targets RanBP1 and phosphoserine phosphatase that regulate centrosome duplication and serine biosynthesis, respectively. Altogether, findings from this study suggest that the NPM1/c-Myc axis could represent a promising therapeutic target to thwart resistance to vemurafenib in BRAF-mutated CC.

BURKITT LYMPHOMA IN GASTROINTESTINAL TRACT: A REPORT OF TWO CASES.

Burkitt lymphoma, a type of non-Hodgkin B-cell lymphoma, is the fastest growing human cancer, presenting pathologically with a 'starry sky' pattern. It is most often found in the abdomen and the jaw, however, localization in the abdomen other than the ileocecal area is very rare and described only in a handful of cases. Standard treatment consists of initial tumor cytoreduction followed by intense chemotherapy. Most of the relapses occur within one year of the diagnosis, while the 5-year survival is around 80%. We present two cases which are specific for unusual location of Burkitt lymphoma in the colon and stomach, in immunocompetent patients with negative Epstein-Barr virus tests. Also, one of the patients presented is one of the oldest ever reported with abdominal Burkitt lymphoma, while the other patient is an example of diagnostic difficulties in distinguishing Burkitt lymphoma from similar lymphomas. Due to the rapidly growing tumors and urgent need for cytoreductive surgery, it is crucial to consider the diagnosis of Burkitt lymphoma even in atypical localizations or absence of the common risk factors associated with Burkitt lymphoma.

Blood Vessel Invasion Is an Independent Prognostic Factor in Endometrial Endometrioid Carcinoma Compared to Lymph Vessel Invasion and Myometrial Invasion Pattern.

We studied 115 cases of EEC diagnosed on hysterectomy specimens. Double immunohistochemical staining (D2-40/CD31) was performed in all 115 cases to show LVI and BVI on the same slide. MELF pattern invasion was present in 24/115 (21%) cases. MELF-positive tumors had a higher frequency of LVI than MELF-negative tumors (58% and 23%, respectively); the frequency of BVI was twice as high in MELF-positive tumors in comparison to MELF-negative tumors (25% and 12%, respectively). These differences were significant (p ˂ 0.0001). All tumors with positive BVI also had a concomitant LVI. The presence of MELF invasion had no impact on overall survival, confirming previous studies. 5-year survival rates were almost equal in cases with negative LVSI and cases with positive isolated LVI (98% vs. 97%). However, in cases where BVI was also present, the 5-year survival rate was significantly lower, 63% (p ˂ 0.0001). Furthermore, BVI proved to be an independent prognostic factor for overall survival, disease-free survival, and recurrence in the multivariate analysis. In conclusion, MELF pattern invasion is a good predictor of lymphatic and blood vessel invasion but has no prognostic value. Our results suggest that BVI in EEC has greater clinical value than isolated LVI or myometrial invasion patterns, and the therapeutic approach should be guided by BVI presence. Therefore, we hope this study will promote the routine evaluation of BVI in the context of EEC diagnostic procedures.

NKG2D-mediated detection of metabolically stressed hepatocytes by innate-like T cells is essential for initiation of NASH and fibrosis.

Metabolic-associated fatty liver disease (MAFLD) is a spectrum of clinical manifestations ranging from benign steatosis to cirrhosis. A key event in the pathophysiology of MAFLD is the development of nonalcoholic steatohepatitis (NASH), which can potentially lead to fibrosis and hepatocellular carcinoma, but the triggers of MAFLD-associated inflammation are not well understood. We have observed that lipid accumulation in hepatocytes induces expression of ligands specific to the activating immune receptor NKG2D. Tissue-resident innate-like T cells, most notably γδ T cells, are activated through NKG2D and secrete IL-17A. IL-17A licenses hepatocytes to produce chemokines that recruit proinflammatory cells into the liver, which causes NASH and fibrosis. NKG2D-deficient mice did not develop fibrosis in dietary models of NASH and had a decreased incidence of hepatic tumors. The frequency of IL-17A+ γδ T cells in the blood of patients with MAFLD correlated directly with liver pathology. Our findings identify a key molecular mechanism through which stressed hepatocytes trigger inflammation in the context of MAFLD.

Accuracy of Controlled Attenuation Parameter and Liver Stiffness Measurement in Patients with Non-alcoholic Fatty Liver Disease.

We evaluated the diagnostic accuracy of the controlled attenuation parameter (CAP) and liver stiffness measurements (LSM) measured with either an M or XL probe against liver biopsy (LB) in patients with non-alcoholic fatty liver disease (NAFLD). This study was a cross-sectional prospective study that included 179 NAFLD patients. With a cutoff value for CAP ≥345, we can exclude significant steatosis in 87% (79.4%-92.5%) of our population. With respect to the LSM, the highest accuracy was obtained for F ≥ F3 (area under the receiver operating characteristic curve [AUROC] = 0.98) and F = F4 (AUROC = 0.98). In a multivariable linear regression model, significant predictors influencing LSM were fibrosis stage (ß = 2.6, p < 0.001) as a positive predictor and lobular inflammation (ß = -0.68, p = 0.04) as a negative predictor, without significant influence after adjustment for CAP and probe type. We found that CAP is a satisfactory method for excluding advanced steatosis, while LSM is a good non-invasive marker for the exclusion of fibrosis.

Rapid Fatal Acute Peripheral T-Cell Lymphoma Associated With IgG Plasma Cell Leukemia and IgA Hypergammaglobulinemia.

Simultaneous occurrence of T-cell and B-cell neoplasms is rare, and etiologic relationships between these 2 malignancies are poorly understood. We describe the case of a 66-year-old woman who was admitted to the hospital because of fever, hemoptysis, lymphadenopathy, and skin rash. Enlarged lymph nodes in axillary, pectoral, paratracheal, and periportal regions as well as slight hepatomegaly and splenomegaly were confirmed. A peripheral blood smear revealed rouleaux formation and numerous circulating plasma cells, with plasmacytoid lymphocytes. Immunofixation-electrophoresis detected a monoclonal band defined as immunoglobulin (IgG)-lambda light chains with broad-band polyclonal IgA. The patient died from abrupt splenic rupture before diagnostic work-up was finished. Postmortem examination revealed infiltration of atypical lymphoid cells exhibiting high proliferative activity admixed with typical and atypical plasma cells in several organs. Thus, plasma cell leukemia (IgG-lambda) as a rare and aggressive variant of plasma cell myeloma in the present case was associated with aggressive peripheral T-cell lymphoma and polyclonal (IgA) plasmacytosis.

Matrix metalloproteinases 2 and 9 immunoexpression in prostate carcinoma at the positive margin of radical prostatectomy specimens.

The aim of this study was to evaluate the expression of matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) in prostate cancer in the main tumor mass and tumor cells at the positive margin as well as the influence of these biomarkers on the biochemical recurrence of the disease in prostatectomy patients. Tissue microarrays of 120 archival prostate carcinoma samples were immunohistochemically evaluated for MMP-2 and MMP-9 expression and compared with clinicopathological parameters. Tumors with positive surgical margins showed significantly higher overall expression of MMP-9 versus tumors with negative resection margins (P = 0.0121). MMP-9 expression was significantly elevated in tumors from patients who had biochemical recurrence (P = 0.0207). In the group of patients with negative margins, MMP-9 expression above the cut-off value was significantly associated with recurrence (P = 0.0065). Multivariate analysis indicated that MMP-9 is a good predictor of biochemical recurrence (odds ratio = 10.29; P = 0.0052). Expression of MMP-2 in tumor cells was significantly higher at the positive margins than in the main tumor mass (P = 0.0301). The present results highlight the potential value of MMP-2 and MMP-9 expression for predicting the behavior of prostate tumors after prostatectomy with both positive and negative surgical margins.