Kandavel Shanmugam

Mutation‐specific antibody detects mutant BRAFV600E protein expression in human colon carcinomas

A point mutation (V600E) in the BRAF oncogene is a prognostic biomarker and may predict for nonresponse to anti‐EGFR antibody therapy in patients with colorectal carcinoma. BRAFV600E mutations are frequently detected in tumors with microsatellite instability and indicate a sporadic origin. We used a mutation‐specific antibody to examine mutant BRAFV600E protein expression and its concordance with BRAFV600E mutation data.

GIV/Girdin is a central hub for profibrogenic signalling networks during liver fibrosis

Progressive liver fibrosis is characterized by the deposition of collagen by activated hepatic stellate cells (HSCs). Activation of HSCs is a multiple receptor-driven process in which profibrotic signals are enhanced, and anti-fibrotic pathways are suppressed. Here we report the discovery of a novel signaling platform comprised of G protein subunit, Gαi and GIV, its guanine exchange factor (GEF), which serves as a central hub within the fibrogenic signalling network initiated by diverse classes of receptors. GIV is expressed in the liver after fibrogenic injury and is required for HSC activation. Once expressed, GIV enhances the profibrotic (PI3K-Akt-FoxO1 and TGFβ-SMAD) and inhibits the anti-fibrotic (cAMP-PKA-pCREB) pathways to skew the signalling network in favor of fibrosis, all via activation of Gαi. We also provide evidence that GIV may serve as a biomarker for progression of fibrosis after liver injury and a therapeutic target for arresting and/or reversing HSC activation during liver fibrosis.

Another look at follicular lymphoma: Immunophenotypic and molecular analyses identify distinct follicular lymphoma subgroups

The aim of this study was to analyse the immunophenotypic and molecular features of a large series of follicular lymphomas, focusing in particular on atypical cases that fail to express CD10 and/or bcl‐2. Such cases present diagnostic pitfalls, especially with regard to the differential diagnosis from follicular hyperplasia and marginal zone B‐cell lymphoma. Therefore, we also included an immunohistochemical evaluation of stathmin, which is strongly expressed by germinal centre B cells, as a putative new marker for follicular lymphomas, particularly those with an atypical phenotype.

Girdin (GIV) Expression as a Prognostic Marker of Recurrence in Mismatch Repair-Proficient Stage II Colon Cancer.

Purpose: Prognostic markers that identify patients with stage II colon cancers who are at the risk of recurrence are essential to personalize therapy. We evaluated the potential of GIV/Girdin as a predictor of recurrence risk in such patients. Experimental Design: Expression of full-length GIV was evaluated by IHC using a newly developed mAb together with a mismatch repair (MMR)-specific antibody panel in three stage II colon cancer patient cohorts, that is, a training (n = 192), test (n = 317), and validation (n = 181) cohort, with clinical follow-up data. Recurrence risk stratification models were established in the training cohort of T3, proficient MMR (pMMR) patients without chemotherapy and subsequently validated. Results: For T3 pMMR tumors, GIV expression and the presence of lymphovascular invasion (LVI) were the only factors predicting recurrence in both training (GIV: HR, 2.78, P = 0.013; LVI: HR, 2.54, P = 0.025) and combined test and validation (pooled) cohorts (GIV: HR, 1.85, P = 0.019; LVI: HR, 2.52, P = 0.0004). A risk model based on GIV expression and LVI status classified patients into high- or low-risk groups; 3-year recurrence-free survival was significantly lower in the high-risk versus low-risk group across all cohorts [Training: 52.3% vs. 84.8%; HR, 3.74, 95% confidence interval (CI), 1.50–9.32; Test: 85.9% vs. 97.9%, HR, 7.83, 95% CI, 1.03–59.54; validation: 59.4% vs. 84.4%, HR, 3.71, 95% CI, 1.24–11.12]. Conclusions: GIV expression status predicts recurrence risk in patients with T3 pMMR stage II colon cancer. A risk model combining GIV expression and LVI status information further enhances prediction of recurrence. Further validation studies are warranted before GIV status can be routinely included in patient management algorithms. Clin Cancer Res; 22(14); 3488–98. ©2016 AACR.

Prognostic value of MACC1 and proficient mismatch repair status for recurrence risk prediction in stage II colon cancer patients: the BIOGRID studies

Background We assessed the novel MACC1 gene to further stratify stage II colon cancer patients with proficient mismatch repair (pMMR). Patients and methods Four cohorts with 596 patients were analyzed: Charité 1 discovery cohort was assayed for MACC1 mRNA expression and MMR in cryo-preserved tumors. Charité 2 comparison cohort was used to translate MACC1 qRT-PCR analyses to FFPE samples. In the BIOGRID 1 training cohort MACC1 mRNA levels were related to MACC1 protein levels from immunohistochemistry in FFPE sections; also analyzed for MMR. Chemotherapy-naïve pMMR patients were stratified by MACC1 mRNA and protein expression to establish risk groups based on recurrence-free survival (RFS). Risk stratification from BIOGRID 1 was confirmed in the BIOGRID 2 validation cohort. Pooled BIOGRID datasets produced a best effect-size estimate. Results In BIOGRID 1, using qRT-PCR and immunohistochemistry for MACC1 detection, pMMR/MACC1-low patients had a lower recurrence probability versus pMMR/MACC1-high patients (5-year RFS of 92% and 67% versus 100% and 68%, respectively). In BIOGRID 2, longer RFS was confirmed for pMMR/MACC1-low versus pMMR/MACC1-high patients (5-year RFS of 100% versus 90%, respectively). In the pooled dataset, 6.5% of patients were pMMR/MACC1-low with no disease recurrence, resulting in a 17% higher 5-year RFS [95% confidence interval (CI) (12.6%-21.3%)] versus pMMR/MACC1-high patients (P = 0.037). Outcomes were similar for pMMR/MACC1-low and deficient MMR (dMMR) patients (5-year RFS of 100% and 96%, respectively). Conclusions MACC1 expression stratifies colon cancer patients with unfavorable pMMR status. Stage II colon cancer patients with pMMR/MACC1-low tumors have a similar favorable prognosis to those with dMMR with potential implications for the role of adjuvant therapy.

569PGIV AS A NOVEL PROGNOSTIC MARKER IN STAGE II COLON CANCER

ABSTRACT Aim: There is an evident unmet need to better define recurrence risk for patients with stage II colon cancer (CC), particularly those with mismatch repair proficient (pMMR) tumors, to determine the subgroup of patients that may benefit from adjuvant chemotherapy. GIV/Girdin is a novel metastasis associated protein that triggers tumor cell invasion by enhancing PI3K/AKT signaling downstream of multiple oncogenic receptors. We explored the potential of GIV as a prognostic marker in stage II CC. Methods: A MMR antibody panel and a GIV specific antibody were developed by Ventana and evaluated by immunohistochemistry (IHC) on a cohort of stage II CC from Melbourne (n = 192), enriched for patients with recurrent disease (n = 44, 25%). Log rank test was used to assess the association of GIV IHC expression status with the recurrence risk. Evaluation of alternative GIV scoring algorithms, combining staining intensity and percent staining, and statistical predictive modeling including the analysis of distant recurrence free survival (DRFS) was undertaken for the chemo-naive cases, stratified by MMR and AJCC tumor (T) status. The association between GIV IHC status and standard histopathologic criteria was also assessed. Results: The distribution of deficient MMR (dMMR) vs pMMR cases were 20.8% and 79.2%, respectively. Within the chemo-naive population (n = 103), expected associations between pathologic features and DRFS were observed, including pMMR vs dMMR (HR 4.12, p = 0.052), T4 vs T3 (HR 2.39, p = 0.055) and lymphovascular invasion (LVI) vs no LVI (HR 2.62, p = 0.021). GIV positivity, defined as >10% of tumor cells stained or any staining of 3+ intensity, was present in 45 (44.0%) of pMMR chemo-naive cases. For T3 pMMR chemo-naive cases (n = 91), GIV positivity was associated with significantly reduced DRFS (HR 2.49, p = 0.022). Adding LVI as an additional parameter to the algorithm for this group increased the HR to 4.74 (95% CI 1.90-11.85). Conclusions: GIV IHC expression status has been found to be associated with T3 disease, pMMR, and DRFS in an initial cohort of stage II CC. This exploratory diagnostic algorithm currently undergoes validation in two independent clinical stage II CC cohorts, with promising preliminary data. Disclosure: P. Waring: received research grant funding from F. Hoffmann-La Roche; B. Lafleur, A. Muranyi, S. Singh and P. Brunhoeber: Employee of Ventana Medical Systems, Inc., a member of the Roche Group; S. Hu, V. Teichgraber, U. Rohr, R. Ridder:. and K. Shanmugam: Employee of F. Hoffmann-La Roche Ltd. All other authors have declared no conflicts of interest.