Pierre-Alexandre Just

Histologic subtypes, immunohistochemistry, FISH or molecular screening for the accurate diagnosis of ALK-rearrangement in lung cancer: A comprehensive study of Caucasian non-smokers

EML4-ALK adenocarcinomas constitute a new molecular subgroup of lung tumours that respond very well to crizotinib, an ALK inhibitor. However, the diagnosis of ALK rearrangement in lung cancer is challenging. The aim of this study was to compare the diagnostic accuracy of five different methods in a series of 20 EGFR(wt/wt) lung adenocarcinomas from non- or light- smokers. Multiplex RT-PCR was considered as gold standard and identified four ALK-rearranged tumours among the 20 tested tumours. qRT-PCR got an interpretability rate of 100% and accurately typed all 20 tumours. qRT-PCR from corresponding formalin-fixed paraffin-embedded (FFPE) specimens got an interpretability rate of 65%. Out of the four previously identified ALK-rearranged cases, three were interpretable and two were retrieved using FFPE qRT-PCR. ALK break-apart FISH got an interpretability rate of 60% and accurately typed all of the twelve remaining cases. Anti-ALK immunohistochemistry (IHC) accurately typed all twenty tumours using a cut-off value of strong staining of 100% tumour cells. The 16 non ALK-rearranged tumours got no/light staining in 13 cases, and a moderate staining of 80-100% tumour cells in 3 cases. We then analysed four solid signet-ring lung adenocarcinomas. FFPE qRT-PCR, FISH and immunohistochemistry were concordant in three cases, with positive and negative results in respectively one and two cases. The fourth case, which was positive by FISH and immunohistochemistry but negative by RT-PCR, was shown to have a non-EML4-ALK ALK-rearrangement. As various factors such as RNA quality, fixation quality and type of ALK rearrangement may impede ALK screening, we propose a combined FISH/molecular biology diagnostic algorithm in which anti-ALK immunohistochemistry is used as a pre-screening step.

The Wnt/β-catenin pathway as a therapeutic target in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death worldwide. However, targeted therapies are still at their beginning for the treatment of this poor-prognosis tumor. Among the signaling cascades deregulated in HCC, the Wnt/β-catenin signaling pathway plays a key role in hepatic oncogenesis. Although it has been shown, using HCC cell lines, that inhibition of the β-catenin signaling has anti-tumoral effect, no molecules targeting the Wnt pathway are currently tested in clinical trials for the treatment of HCC. Here we review our current knowledge about the role of the Wnt/β-catenin pathway in hepatocellular carcinoma pathogenesis and the benefits and limits of targeting this pathway in HCC.

TWIST1 a new determinant of epithelial to mesenchymal transition in EGFR mutated lung adenocarcinoma.

Metastasis is a multistep process and the main cause of mortality in lung cancer patients. We previously showed that EGFR mutations were associated with a copy number gain at a locus encompassing the TWIST1 gene on chromosome 7. TWIST1 is a highly conserved developmental gene involved in embryogenesis that may be reactivated in cancers promoting both malignant conversion and cancer progression through an epithelial to mesenchymal transition (EMT). The aim of this study was to investigate the possible implication of TWIST1 reactivation on the acquisition of a mesenchymal phenotype in EGFR mutated lung cancer. We studied a series of consecutive lung adenocarcinoma from Caucasian non-smokers for which surgical frozen samples were available (n = 33) and showed that TWIST1 expression was linked to EGFR mutations (P<0.001), to low CDH1 expression (P<0.05) and low disease free survival (P = 0.044). To validate that TWIST1 is a driver of EMT in EGFR mutated lung cancer, we used five human lung cancer cell lines and demonstrated that EMT and the associated cell mobility were dependent upon TWIST1 expression in cells with EGFR mutation. Moreover a decrease of EGFR pathway stimulation through EGF retrieval or an inhibition of TWIST1 expression by small RNA technology reversed the phenomenon. Collectively, our in vivo and in vitro findings support that TWIST1 collaborates with the EGF pathway in promoting EMT in EGFR mutated lung adenocarcinoma and that large series of EGFR mutated lung cancer patients are needed to further define the prognostic role of TWIST1 reactivation in this subgroup.

Identification by FFPE RNA-Seq of a new recurrent inversion leading to RBM10-TFE3 fusion in renal cell carcinoma with subtle TFE3 break-apart FISH pattern

Gene fusions involving TFE3 defines the “Xp11.2 translocations” subclass of renal cell carcinomas (RCCs) belonging to the MiT family translocation RCC. Four recurrent TFE3 fusion partners were identified to date: PRCC, ASPSCR1, SFPQ, and NONO. Break‐apart TFE3 fluorescence in situ hybridization (FISH) on formalin‐fixed and paraffin‐embedded (FFPE) tissue sections is currently the gold standard for identification of TFE3 rearrangements. Herein, we report a case of RCC with a morphological appearance of Xp11.2 translocation, and positive TFE3 immunostaining. By FISH, the spots constituting the split signal were barely spaced, suggestive of a chromosome X inversion rather than a translocation. We performed RNA‐seq from FFPE material to test this hypothesis. RNA‐seq suggested a fusion of RBM10 gene exon 17 (Xp11.23) with TFE3 gene exon 5 (Xp11.2). RBM10‐TFE3 fusion transcript was confirmed using specific RT‐PCR. Our work showed that RNA‐Seq is a robust technique to detect fusion transcripts from FFPE material. A RBM10‐TFE3 fusion was previously described in single case of Xp11.2 RCC. Although rare, RBM10‐TFE3 fusion variant (from chromosome X paracentric inversion), therefore, appears to be a recurrent molecular event in Xp11.2 RCCs. RBM10‐TFE3 fusion should be added in the list of screened fusion transcripts in targeted molecular diagnostic multiplex RT‐PCR.

A case of pericoronary pseudotumor due to localized Castleman's disease

BACKGROUND A 59-year-old male had a latent epicardial mass discovered at cardiovascular imaging during the assessment of an aortic murmur. RESULTS The resected mass surrounded the left anterior descending coronary artery. It was a well-limited pericoronary cellular lesion. It was made of a mixture of polytypic plasma cells, lymphocytes with lymphoid follicles, hyaline vascular hyperplasia, and focal eosinophils. No immunoglobulin and TCR-gamma gene rearrangements were detected. In this immunocompetent patient, HHV-8 was negative. CONCLUSION The pattern was consistent with a pericoronary localized Castlemans disease of composite histologic subtype.

Neurotensin receptor 1 antagonist SR48692 improves response to carboplatin by enhancing apoptosis and inhibiting drug efflux in ovarian cancer

Purpose: The high affinity receptor 1 (NTSR1) and its agonist, neurotensin (NTS), are correlated with tumor cell aggressiveness in most solid tumors. As chemoresistance and tumor aggressiveness are often related, we decided to study the role of the NTSR1 complex within platinum-based chemotherapy responses. In an ovarian model, we studied carboplatin because it is the main standard of care for ovarian cancer. Experimental Design: Experimental tumors and in vitro studies were performed using SKOV3 and A2780 cells treated with carboplatin, with or without a very specific NTSR1 antagonist, SR48692. We measured the effects of these treatments on cell apoptosis and apoptosis-related proteins, platinum accumulation in the cell and nucleus, and the expression and localization of platinum transporters. NTS and NTSR1 labeling was measured in patients with ovarian cancer. Results: SR48692 enhanced the response to carboplatin in ovarian cancer cells and experimental tumors. When SR48692 is combined with carboplatin, we noted a major improvement of platinum-induced DNA damage and cell death, as well as a decrease in tumor growth. The relationship of these results to clinical studies was made by the detection of NTS and NTSR1 in 72% and 74% of ovarian cancer, respectively. Furthermore, in a large series of high-grade ovarian cancer, NTSR1 mRNA was shown to correlate with higher stages and platinum resistance. Conclusions: This study strongly suggests that the addition of NTSR1 inhibitor in combination with platinum salt–based therapy will improve the response to the drug. Clin Cancer Res; 23(21); 6516–28. ©2017 AACR.

Inhibin A and inhibin B producing ovarian fibrothecoma revealed by suppression of follicle stimulating hormone (FSH) in a post-menopausal woman: report of the first case

Abstract In this report, we describe the first case ever reported in the literature, of an inhibin-A (INHA) and inhibin-B (INHB) producing fibrothecoma. A post-menopausal woman was referred to our unit because of follicle stimulating hormone (FSH) level below the reference interval for postmenopausal women. By contrast luteinizing hormone, hCG, and estradiol levels were within normal range. This discrepancy suggested the secretion of FSH inhibitory factors. INHB and INHA levels were markedly elevated for age, 475 pg/mL and 100 pg/mL, respectively. Ultrasonography and MRI showed a pelvic mass of indeterminate nature. Abnormal inhibin secretion is generally observed in granulosa cell tumors. In this case this etiology was unlikely because of low estradiol and AMH levels. Surgical exploration revealed a 10 cm mass of the left ovary proven histologically to be an ovarian fibrothecoma (OFT). After tumor removal, INHB and INHA levels decreased rapidly. Only three cases of OFT with an important secretion of INHB have been reported to date. INHA secretion has never been associated with OFT. There is a need to develop coupled hormone and imaging strategies to diagnose the source of INH secretion in case of FSH/LH discrepancy.