High-throughput characterization of functional variants highlights heterogeneity and polygenicity underlying lung cancer susceptibility.

Genome-wide association studies (GWASs) have identified numerous lung cancer risk-associated loci. However, decoding molecular mechanisms of these associations is challenging since most of these genetic variants are non-protein-coding with unknown function. Here, we implemented massively parallel reporter assays (MPRAs) to simultaneously measure the allelic transcriptional activity of risk-associated variants. We tested 2,245 variants at 42 loci from 3 recent GWASs in East Asian and European populations in the context of two major lung cancer histological types and exposure to benzo(a)pyrene. This MPRA approach identified one or more variants (median 11 variants) with significant effects on transcriptional activity at 88% of GWAS loci. Multimodal integration of lung-specific epigenomic data demonstrated that 63% of the loci harbored multiple potentially functional variants in linkage disequilibrium. While 22% of the significant variants showed allelic effects in both A549 (adenocarcinoma) and H520 (squamous cell carcinoma) cell lines, a subset of the functional variants displayed a significant cell-type interaction. Transcription factor analyses nominated potential regulators of the functional variants, including those with cell-type-specific expression and those predicted to bind multiple potentially functional variants across the GWAS loci. Linking functional variants to target genes based on four complementary approaches identified candidate susceptibility genes, including those affecting lung cancer cell growth. CRISPR interference of the top functional variant at 20q13.33 validated variant-to-gene connections, including RTEL1, SOX18, and ARFRP1. Our data provide a comprehensive functional analysis of lung cancer GWAS loci and help elucidate the molecular basis of heterogeneity and polygenicity underlying lung cancer susceptibility.

Cross-talk between EGFR and BMP signals regulates chondrocyte maturation during endochondral ossification.

BACKGROUND: Progressive maturation of growth plate chondrocytes drives long bone growth during endochondral ossification. Signals from the epidermal growth factor receptor (EGFR), and from bone morphogenetic protein-2 (BMP2), are required for normal chondrocyte maturation. Here, we investigated cross-talk between EGFR and BMP2 signals in developing and adult growth plates. RESULTS: Using in vivo mouse models of conditional cartilage-targeted EGFR or BMP2 loss, we show that canonical BMP signal activation is increased in the hypertrophic chondrocytes of EGFR-deficient growth plates; whereas EGFR signal activation is increased in the reserve, prehypertrophic and hypertrophic chondrocytes of BMP2-deficient growth plates. EGFR-deficient chondrocytes displayed increased BMP signal activation in vitro, accompanied by increased expression of IHH, COL10A1, and RUNX2. Hypertrophic differentiation and BMP signal activation were suppressed in normal chondrocyte cultures treated with the EGFR ligand betacellulin, effects that were partially blocked by simultaneous treatment with BMP2 or a chemical EGFR antagonist. CONCLUSIONS: Cross-talk between EGFR and BMP2 signals occurs during chondrocyte maturation. In the reserve and prehypertrophic zones, BMP2 signals unilaterally suppress EGFR activity; in the hypertrophic zone, EGFR and BMP2 signals repress each other. This cross-talk may play a role in regulating chondrocyte maturation in developing and adult growth plates.

Carcinoma -associated Retinopathy(CAR): Role of Electroretinography(ERG) and Optical coherence Tomography(OCT) in diagnosis and predicting treatment outcome.

PURPOSE: Cancer-associated retinopathy (CAR) is a potentially blinding condition that can be stalled or,rarely, reversed if diagnosed early. This case report aims to highlight the role of Electroretinography (ERG) and Optical Coherence Tomography (OCT) in diagnosis and predicting treatment response, in the clinical scenario of unexplained vision loss in a patient with a recent diagnosis of uterine malignancy. OBSERVATIONS: A 70 year old lady, recently diagnosed with Endometrial carcinoma Stage 3, came to us with defective vision and photopsiae of both eyes of ten days duration. A high index of suspicion, flat ERG, OCT changes, absence of metastasis, and positive Antirecoverin antibody clinched the diagnosis. Early systemic steroid therapy along with surgical removal of the tumour, adjuvant radiotherapy and chemotherapy helped in visual improvement in our patient. CONCLUSIONS: Presence of intact ellipsoid zone (EZ) and external limiting membrane (ELM) in pre-treatment OCT was found to be a positive predictor of visual recovery.

Recent advances in granulosa cell tumor ovary: a review.

Granulosa cell tumors constitute less than 5 % of all ovarian tumors. Unlike epithelial ovarian tumors, they occur in a younger age group, are usually detected in an early stage and often have features of hyperestrogenism. The presenting symptoms are usually nonspecific with abdominal pain or distension. They follow an indolent course and are characterized by a long natural history. Mutation of FOXL2 (402C->G) seen in 97 % of adult GCT may be pathognomonic for adult GCT. Only stage of the disease has been consistently shown in various studies to affect survival of patients with GCT. The initial management of patients, for whom fertility is not an issue, is total abdominal hysterectomy, bilateral salpingo-oophorectomy and removal of all gross disease. Nodal dissection is not a significant factor for survival and is not recommended in surgical staging of GCT. Fertility preserving surgery with unilateral salpingo-oophorectomy is feasible in young patients with stage Ia GCT. Patients with early stage disease (stage I and II) have a very good prognosis with 5 year DFS and OS of 89 % and 99 % respectively and these groups of patients usually don't require any postoperative treatment. Patients with stage Ic disease associated with poor prognostic factors like large tumor size or high mitotic index and stage II, have a higher chance of relapse, and may benefit with postoperative treatment but role of chemotherapy is still debatable. In advanced stage disease (stage III and IV) the 5 year DFS and OS disease was 72 % and 80 % respectively hence the option of postoperative treatment with 6 cycles of BEP should be considered in this group. Recently paclitaxel is being investigated as an effective tool in GCT. The efficacy of radiation in GCT is not well defined but in optimally debulked cases postoperative radiation is a viable option. Due to high chance of recurrence even years after apparent clinical cure of the primary tumor, lifelong follow up with clinical examination and tumor markers like inhibin B is recommended. About 25 % GCT develop recurrence and the median time to recur is usually 4-5 years. Most recurrences are intraperitoneal and usually a complete debulking of the disease is feasible even in the recurrent setting. Postoperative chemotherapy (platinum based) is usually given after surgery more so in cases with widespread disease or after suboptimal cytoreduction. Recurrent chemoresistant, progressive non-responding GCT or patients with high surgical risk are ideal candidates for targeted therapy.