Comparison of actionable events detected in cancer genomes by whole-genome sequencing, in silico whole-exome and mutation panels.

BACKGROUND: Next-generation sequencing is used in cancer research to identify somatic and germline mutations, which can predict sensitivity or resistance to therapies, and may be a useful tool to reveal drug repurposing opportunities between tumour types. Multigene panels are used in clinical practice for detecting targetable mutations. However, the value of clinical whole-exome sequencing (WES) and whole-genome sequencing (WGS) for cancer care is less defined, specifically as the majority of variants found using these technologies are of uncertain significance. PATIENTS AND METHODS: We used the Cancer Genome Interpreter and WGS in 726 tumours spanning 10 cancer types to identify drug repurposing opportunities. We compare the ability of WGS to detect actionable variants, tumour mutation burden (TMB) and microsatellite instability (MSI) by using in silico down-sampled data to mimic WES, a comprehensive sequencing panel and a hotspot mutation panel. RESULTS: We reveal drug repurposing opportunities as numerous biomarkers are shared across many solid tumour types. Comprehensive panels identify the majority of approved actionable mutations, with WGS detecting more candidate actionable mutations for biomarkers currently in clinical trials. Moreover, estimated values for TMB and MSI vary when calculated from WGS, WES and panel data, and are dependent on whether all mutations or only non-synonymous mutations were used. Our results suggest that TMB and MSI thresholds should not only be tumour-dependent, but also be sequencing platform-dependent. CONCLUSIONS: There is a large opportunity to repurpose cancer drugs, and these data suggest that comprehensive sequencing is an invaluable source of information to guide clinical decisions by facilitating precision medicine and may provide a wealth of information for future studies. Furthermore, the sequencing and analysis approach used to estimate TMB may have clinical implications if a hard threshold is used to indicate which patients may respond to immunotherapy.

Estimating the growth rate of infection during the early phase of a pandemic like COVID-19.

At the very outbreak of a pandemic, it is very important to be able to assess the spreading rate of the disease i.e., the rate of increase of infected people in a specific locality. Combating the pandemic situation critically depends on an early and correct prediction of, to what extent the disease may possibly grow within a short period of time. This paper attempts to estimate the spreading rate by counting the total number of infected persons at times. Adaptive clustering is especially suitable for forming clusters of infected persons distributed spatially in a locality and successive sampling is used to measure the growth in number of infected persons. We have formulated a 'chain ratio to regression type estimator of population total' in two occasions adaptive cluster successive sampling and studied the properties of the estimator. The efficacy of the proposed strategy is demonstrated through simulation technique as well as real life population which is followed by suitable recommendation.

Gestational folate deficiency alters embryonic gene expression and cell function.

Folic acid is a nutrient essential for embryonic development. Folate deficiency can cause embryonic lethality or neural tube defects and orofacial anomalies. Folate receptor 1 (Folr1) is a folate binding protein that facilitates the cellular uptake of dietary folate. To better understand the biological processes affected by folate deficiency, gene expression profiles of gestational day 9.5 (gd9.5) Folr1-/- embryos were compared to those of gd9.5 Folr1+/+ embryos. The expression of 837 genes/ESTs was found to be differentially altered in Folr1-/- embryos, relative to those observed in wild-type embryos. The 837 differentially expressed genes were subjected to Ingenuity Pathway Analysis. Among the major biological functions affected in Folr1-/- mice were those related to 'digestive system development/function', 'cardiovascular system development/function', 'tissue development', 'cellular development', and 'cell growth and differentiation', while the major canonical pathways affected were those associated with blood coagulation, embryonic stem cell transcription and cardiomyocyte differentiation (via BMP receptors). Cellular proliferation, apoptosis and migration were all significantly affected in the Folr1-/- embryos. Cranial neural crest cells (NCCs) and neural tube explants, grown under folate-deficient conditions, exhibited marked reduction in directed migration that can be attributed, in part, to an altered cytoskeleton caused by perturbations in F-actin formation and/or assembly. The present study revealed that several developmentally relevant biological processes were compromised in Folr1-/- embryos.

Whole-genome sequencing reveals clinically relevant insights into the aetiology of familial breast cancers.

BACKGROUND: Whole-genome sequencing (WGS) is a powerful method for revealing the diversity and complexity of the somatic mutation burden of tumours. Here, we investigated the utility of tumour and matched germline WGS for understanding aetiology and treatment opportunities for high-risk individuals with familial breast cancer. PATIENTS AND METHODS: We carried out WGS on 78 paired germline and tumour DNA samples from individuals carrying pathogenic variants in BRCA1 (n = 26) or BRCA2 (n = 22) or from non-carriers (non-BRCA1/2; n = 30). RESULTS: Matched germline/tumour WGS and somatic mutational signature analysis revealed patients with unreported, dual pathogenic germline variants in cancer risk genes (BRCA1/BRCA2; BRCA1/MUTYH). The strategy identified that 100% of tumours from BRCA1 carriers and 91% of tumours from BRCA2 carriers exhibited biallelic inactivation of the respective gene, together with somatic mutational signatures suggestive of a functional deficiency in homologous recombination. A set of non-BRCA1/2 tumours also had somatic signatures indicative of BRCA-deficiency, including tumours with BRCA1 promoter methylation, and tumours from carriers of a PALB2 pathogenic germline variant and a BRCA2 variant of uncertain significance. A subset of 13 non-BRCA1/2 tumours from early onset cases were BRCA-proficient, yet displayed complex clustered structural rearrangements associated with the amplification of oncogenes and pathogenic germline variants in TP53, ATM and CHEK2. CONCLUSIONS: Our study highlights the role that WGS of matched germline/tumour DNA and the somatic mutational signatures can play in the discovery of pathogenic germline variants and for providing supporting evidence for variant pathogenicity. WGS-derived signatures were more robust than germline status and other genomic predictors of homologous recombination deficiency, thus impacting the selection of platinum-based or PARP inhibitor therapy. In this first examination of non-BRCA1/2 tumours by WGS, we illustrate the considerable heterogeneity of these tumour genomes and highlight that complex genomic rearrangements may drive tumourigenesis in a subset of cases.

Narrow-linewidth broadly tunable Yb-doped Q-switched fiber laser using multimode interference filter.

A narrow-linewidth broadly tunable Yb-doped Q-switched fiber laser using an acousto-optic modulator and multimode interference filter (MMIF) in the linear bulk cavity resonator and an all-fiber ring cavity resonator has been demonstrated. Insertion of an MMIF in the linear cavity resonator using bulk components decreased the spectral bandwidth of the Q-switched signal by two orders of magnitude from 11 to less than 0.1 nm. Spectral tunability of more than 16 nm in the range from 1057 to 1073 nm has also been achieved by the combination of MMIF and a standard polarization controller (SPC). A decrease in the pulse duration with a decrease in the spectral bandwidth of the output signal has also been recorded. The pulse duration of the Q-switched signal was reduced from ∼305 to ∼240 ns by the introduction of the MMIF in the resonator at the same value of the input pump power. In the case of the all-fiber Q-switched ring cavity resonator, the spectral bandwidth of the Q-switched signal was reduced by two orders of magnitude from ∼17 to less than 0.1 nm due to the introduction of the MMIF in the resonator. The spectral tunability of more than 12 nm in the range from 1038 to 1050 nm was achieved by an MMIF and an SPC.

Melanocyte transformation requires complete loss of all pocket protein function via a mechanism that mitigates the need for MAPK pathway activation.

Deregulation of p16INK4A is a critical event in melanoma susceptibility and progression. It is generally assumed that the major effect of loss of p16 function is mediated through the CDK-cyclin pathway via its influence on the pocket protein (PP) pRb. However, there are also two other PPs, p107 and p130, which, when phosphorylated by CDK-cyclin complexes, play a role in permitting cell progression. Cohorts of mice carrying melanocyte-specific knockouts (KOs) of various combinations of the three PPs were generated. Mice null for pRb, p107, p130 or any combination of double mutants did not develop melanoma. Surprisingly, melanocyte-specific loss of all three PPs facilitated melanoma development (median age of onset 308 days, penetrance 40% at 1 year). Tumorigenesis was exacerbated by Trp53 co-deletion (median age of onset 275 days, penetrance 82% at 1 year), with cell culture studies indicating that this difference may result from the apoptotic role of Trp53. Melanomas in PP;Trp53-deficient mice lacked either Ras or Braf mutations, and hence developed in the absence of constitutive MAPK pathway activation. The lag period between induction of total PP or PP/Trp53 KO and melanoma development indicates that additional genetic or epigenetic alterations may account for neoplastic progression. However, exome sequencing of PP;Trp53 KO melanomas failed to reveal any additional recurrent driver mutations. Analysis of the putative mutation signature of the PP;Trp53 KO melanomas suggests that melanocytes are primed for transformation via a mutagenic mechanism involving an excess of T>G substitutions, but not involving a preponderance of C>T substitutions at CpG sites, which is the case for most spontaneous cancers not driven by a specific carcinogen. In sum, deregulation of all three PPs appears central to neoplastic progression for melanoma, and the customary reference to the p16INKA/CDK4/pRB pathway may no longer be accurate; all PPs are potentially critical targets of CDK-cyclins in melanoma.

Snakebite mediated acute kidney injury, prognostic predictors, oxidative and carbonyl stress: A prospective study.

Snake bite is an occupational hazard in India and important preventable cause of acute kidney injury (AKI). This study was done to estimate the magnitude of snakebite-induced AKI (SAKI) who required renal replacement therapy, prognostic predictors, and final outcome, and to measure the oxidative and carbonyl stress (CS) level in SAKI patient who underwent hemodialysis (HD). All SAKI patients dialyzed between April 2010 and July 2011 in NRS Medical College were included. Demographical, clinical, and biochemical data were analyzed, and patients are followed to discharge or death. Oxidative and CS markers (advanced oxidation protein product [AOPP], advanced glycation end product, pentosidine, dityrosine, thioberbituric acid reactive substance, and methylglyoxal [MG]) were measured in 48 SAKI patient requiring HD. About 155 SAKI patients (M: F 2.2:1) received HD. Of them. The age was 36.2 (range 4-74) years. The most common site of the bite was lower limb (88.7%). Oliguria and bleeding manifestation were the common presentation. Hypotension was found in 52 (33.5%) cases, cellulitis and inflammation were found in about 63%. Mean creatinine was 4.56 ± 0.24 mg/dl. About 42 (27.1%) had disseminated intravascular coagulation (DIC). 36 (78.2%) had cellulites, 24 (52.2%) had hypotension or shock at initial presentation (P < 0.05), bleeding manifestation was found in 37 (80.4%), and 22 (47.8%) had DIC (P < 0.05). Forty-six (29.7%) patient died. DIC and hypotension/shock at initial presentation came out as an independent predictor of death. Among all markers measured for oxidative and CS (n = 48) AOPP and MG came out as an independent predictor (P < 0.05) of adverse outcome. Hypotension, DIC, AOPP, and MG were a poor prognostic marker in SAKI patients requiring dialysis.

Temporomandibular Joint Disc Repositioning Using an Orthopedic Suture Anchor: A Modified Disc Anchoring Technique.

PURPOSE: The study assessed the efficacy of orthopedic suture anchor as a modified suture anchor for disc repositioning in case of a closed lock of TMJ. PATIENT AND METHODS: Disc repositioning was undertaken via a mini preauricular approach. The disc was repositioned on the surface of the condyle and stabilized using an orthopedic suture anchor. Postoperatively functional outcomes were assessed in terms of reduction in pain, joint movement and absence of joint noise and clicking sounds. Postoperative MRI was used to assess the disc position and morphological changes in the disc and arthritic changes in the condyle at the end of six months. RESULTS: Patients were post surgically followed up at regular intervals of 1, 3 and 6 months. Patient experienced significant improvement in mouth opening with good functional outcomes and stable repositioning of disc as noticed By MRI at the end of six months. CONCLUSIONS: We describe a modified technique of disc repositioning using an orthopedic suture anchor for more favorable disc position and joint function. However the long term functional sequel of the procedure and changes in the articular disc needs to be assessed.

'Y' Modification of the Transconjunctival Approach for Management of Zygomatic Complex Fractures: A Prospective Analysis.

PURPOSE: The purpose of this study was to clinically and radiologically evaluate reduction and fixation of isolated zygomatic complex (ZMC) fractures treated by Y modification of the transconjunctival approach. PATIENTS AND METHODS: A prospective evaluation of ten patients was undertaken for a period of 6 months using this modified approach from Jan 2012 to Jun 2013. Patients were examined preoperatively and post operatively at the end of 6 months for symmetry discrepancies involving A-P globe projection, lateral canthal level, malar projection and diplopia in direct and extreme gazes. Cosmetic outcomes were assessed by clinical assessment and examination of photographs. Quality of reduction and stability of fixation was assessed by examination of postoperative images. RESULTS: All patients underwent a three point fixation of ZMC with reconstruction of the orbital floor using titanium mesh. Patients were post surgically followed up at regular intervals of 1, 3 and 6 months. Immediate complications noted were chemosis, lid edema and lower lid retraction. Late complications included minor scleral show in two cases. All patients experienced significant improvement with excellent esthetic appearance and function. CONCLUSIONS: Y modification of transconjunctival approach provides excellent surgical exposure for ZMC fractures potentially avoiding the use of a second incision in the area of ZF suture. Although this technique provides good exposure and excellent esthetics, it requires more operating time and detailed knowledge of the anatomy of the lateral canthal region.

Murine melanomas accelerated by a single UVR exposure carry photoproduct footprints but lack UV signature C>T mutations in critical genes.

Ultraviolet radiation (UVR) exposure increases malignant melanoma (MM) risk, but in the context of acute, not cumulative exposure. C>T and CC>TT changes make up the overwhelming majority of single base substitutions (SBS) in MM DNA, as both precursor melanocytes and melanocytic lesions have incurred incidental exposures to sunlight. To study the mutagenic mechanisms by which acute sunburn accelerates MM, we sequenced the exomes of spontaneous and neonatal UVB-induced Cdk4-R24C::Tyr-NRASQ61K mouse MMs. UVR-induced MMs carried more SBSs than spontaneous MMs, but the levels of genomic instability, reflected by translocations and copy number changes, were not different. C>T/G>A was the most common SBS in spontaneous and UVR-induced MMs, only modestly increased in the latter. However, they tended to occur at the motif A/GpCpG (reflecting C>T transition due to spontaneous deamination of cytosine at CpG) in spontaneous MMs, and T/CpCpC/T (reflecting the effects of pyrimidine dimers on either side of the mutated C) in UVR-induced MMs. Unlike MMs associated with repetitive exposures, we observed no CC>TT changes. In addition, we also found UVR 'footprints' at T>A/A>Ts (at NpTpT) and T>C/A>G (at CpTpC). These footprints are also present in MMs from a chronic UVR mouse model, and in some human MMs, suggesting that they may be minor UVR signature changes. We found few significantly somatically mutated genes (~6 per spontaneous and 15 per UVR-induced melanoma) in addition to the Cdk4 and NRAS mutations already present. Trp53 was the most convincing recurrently mutated gene; however, in the UVR-induced MMs no Trp53 mutations were at C>T/G>A, suggesting that it was probably mutated during tumour progression, not directly induced by UVR photoproducts. The very low load of recurrent mutations convincingly induced by classical UVB-induced dimer photoproducts may support a role for cell extrinsic mechanisms, such as photoimmunosuppression and inflammation in driving MM after acute UVB exposure.

Melanoma susceptibility as a complex trait: genetic variation controls all stages of tumor progression.

Susceptibility to most common cancers is likely to involve interaction between multiple low risk genetic variants. Although there has been great progress in identifying such variants, their effect on phenotype and the mechanisms by which they contribute to disease remain largely unknown. We have developed a mouse melanoma model harboring two mutant oncogenes implicated in human melanoma, CDK4(R24C) and NRAS(Q61K). In these mice, tumors arise from benign precursor lesions that are a recognized strong risk factor for this neoplasm in humans. To define molecular events involved in the pathway to melanoma, we have for the first time applied the Collaborative Cross (CC) to cancer research. The CC is a powerful resource designed to expedite discovery of genes for complex traits. We characterized melanoma genesis in more than 50 CC strains and observed tremendous variation in all traits, including nevus and melanoma age of onset and multiplicity, anatomical site predilection, time for conversion of nevi to melanoma and metastases. Intriguingly, neonatal ultraviolet radiation exposure exacerbated nevus and melanoma formation in most, but not all CC strain backgrounds, suggesting that genetic variation within the CC will help explain individual sensitivity to sun exposure, the major environmental skin carcinogen. As genetic variation brings about dramatic phenotypic diversity in a single mouse model, melanoma-related endophenotype comparisons provide us with information about mechanisms of carcinogenesis, such as whether melanoma incidence is dependent upon the density of pre-existing nevus cells. Mouse models have been used to examine the functional role of gene mutations in tumorigenesis. This work represents their next phase of development to study how biological variation greatly influences lesion onset and aggressiveness even in the setting of known somatic driver mutations.

Changing histologic spectrum of adult nephrotic syndrome over five decades in north India: A single center experience.

Glomerular diseases are an important cause of chronic renal failure in developing countries. The spectrum of diseases causing nephrotic syndrome is changing globally in the last few decades. The aim of this prospective study was to look at this spectrum at a tertiary care center in North India and to analyze the changing trends over the last five decades. Patients in the age group 18-60 years with nephrotic syndrome were consecutively included in the study. Renal biopsies were performed in all patients and were subjected to light microscopy, immunofluorescence (IF) and electron microscopy (EM). While the IF was performed in 78% of cases, EM was available in one-fourth of cases. During 2002-2007, 364 patients (60.2% males) were included in the study. The mean age was 31.5 years. Primary glomerular diseases accounted for 89% of cases while lupus nephritis was the most common secondary glomerular disease. Focal segmental glomerulosclerosis (FSGS) accounted for 30.6% of primary glomerular diseases making it the most common cause of nephrotic syndrome. It was followed by membranous glomerulonephritis (MGN) in 24.4%, mesangiocapillary glomerulonephritis in 17.9% and minimal change disease in 14.8%. In the age group >40 years, MGN was the most common lesion (32.5%) followed by FSGS (27.7%). Over the last five decades, there was a nearly five-fold increase in the incidence of FSGS, 3-fold increase in MGN and a 10-fold reduction in diffuse proliferative glomerulonephritis while there was no major change in incidence of other diseases. The biopsy diagnosis of FSGS has increased considerably in last few decades and it is now the most common cause of nephrotic syndrome in adults in North India. MGN is the most common lesion in patients over 40 years of age.

A potent Chk1 inhibitor is selectively cytotoxic in melanomas with high levels of replicative stress.

There are few effective treatments for metastatic melanoma. Checkpoint kinase 1 (Chk1) inhibitors are being trialled for their efficacy in enhancing conventional chemotherapeutic agents, but their effectiveness as single agents is not known. We have examined the effectiveness of two novel Chk1 selective inhibitors, AR323 and AR678, in a panel of melanoma cell lines and normal cell types. We demonstrate that these drugs display single-agent activity, with IC50s in the low nanomolar range. The drugs produce cytotoxic effects in cell lines that are most sensitive to these drugs, whereas normal cells are only sensitive to these drugs at the higher concentrations where they have cytostatic activity. The cytotoxic effect is the consequence of inhibition of S-phase Chk1, which drives cells prematurely from late S phase into an aberrant mitosis and results in either failure of cytokinesis or cell death through an apoptotic mechanism. The sensitivity to the Chk1 inhibitors was correlated with the level of endogenous DNA damage indicating replicative stress. Chk1 inhibitors are viable single-agent therapies that target melanoma cells with high levels of endogenous DNA damage. This sensitivity suggests that Chk1 is a critical component of an adaptation to replicative stress in these cells. It also suggests that markers of DNA damage may be useful in identifying the melanomas and potentially other tumour types that are more likely to be sensitive to Chk1 inhibitors as single agents.

Glucocorticoid receptor dimerization is required for proper recovery of LPS-induced inflammation, sickness behavior and metabolism in mice.

Endogenous glucocorticoids are essential for mobilizing energy resources, restraining inflammatory responses and coordinating behavior to an immune challenge. Impaired glucocorticoid receptor (GR) function has been associated with impaired metabolic processes, enhanced inflammation and exaggerated sickness and depressive-like behaviors. To discern the molecular mechanisms underlying GR regulation of physiologic and behavioral responses to a systemic immune challenge, GR(dim) mice, in which absent GR dimerization leads to impaired GR-DNA-binding-dependent mechanisms but intact GR protein-protein interactions, were administered low-dose lipopolysaccharide (LPS). GR(dim)-LPS mice exhibited elevated and prolonged levels of plasma corticosterone (CORT), interleukin (IL)-6 and IL-10 (but not plasma tumor necrosis factor-α (TNFα)), enhanced early expression of brain TNFα, IL-1ß and IL-6 mRNA levels, and impaired later central TNFα mRNA expression. Exaggerated sickness behavior (lethargy, piloerection, ptosis) in the GR(dim)-LPS mice was associated with increased early brain proinflammatory cytokine expression and late plasma CORT levels, but decreased late brain TNFα expression. GR(dim)-LPS mice also exhibited sustained locomotor impairment in the open field, body weight loss and metabolic alterations measured by indirect calorimetry, as well as impaired thermoregulation. Taken together, these data indicate that GR dimerization-dependent DNA-binding mechanisms differentially regulate systemic and central cytokine expression in a cytokine- and time-specific manner, and are essential for the proper regulation and recovery of multiple physiologic responses to low-dose endotoxin. Moreover, these results support the concept that GR protein-protein interactions are not sufficient for glucocorticoids to exert their full anti-inflammatory effects and suggest that glucocorticoid responses limited to GR monomer-mediated transcriptional effects could predispose individuals to prolonged behavioral and metabolic sequelae of an enhanced inflammatory state.

Polyarteritis nodosa presenting with spontaneous perirenal hematoma.

Spontaneous perirenal hematoma following ruptured microaneurysm is an unusual but serious complication of polyarteritis nodosa. We describe a young male who presented with spontaneous perirenal hematoma and was subsequently diagnosed to have polyarteritis nodosa. He was managed with immunosuppressive medications with no recurrence of symptoms.

Predictive value of bedside clinical signs and symptoms in early diagnosis of deep vein thrombosis in acutely ill medical patients with special reference to deep vein thrombosis prophylaxis.

Deep vein thrombosis (DVT) is highly elusive in the sense, that being so common among acutely ill hospitalised patients with multiple risk factors yet remain mostly unrecognised particularly at the early stage. Pulmonary thrombo-embolism (PTE), the most sinister acute complication of DVT carries a high mortality on one hand and involves expensive medicare and investigations on the other hand. Many studies that have been undertaken in recent past on this important clinical issue have produced a wealth of published data to show that in the absence of prophylaxis for DVT in such a setting the mortality rates were significantly high. The need to exphasise importance of DVT prophylaxis has now become a unified word in the management of acutely ill medical patient. This article emphasises the advantages of astute bedside clinical examination in identifying DVT early and the need for prophylaxis to prevent this morose condition.

Transmission of human immunodeficiency virus infection by renal transplantation.

The rare occurrence of human immunodeficiency virus (HIV) transmission through organ transplantation cannot override the huge impact that it has on the patient. We report a case of HIV transmission by renal transplantation in a 33-year-old housewife, who received a living related transplantation from her sister. Both the patient and her donor were negative by HIV antibody testing prior to transplantation, but were found to be infected in the ninth month after transplant. Further testing suggested that the donor was in the window period at the time of organ donation after having acquired the infection from her husband.

MUC16 induced rapid G2/M transition via interactions with JAK2 for increased proliferation and anti-apoptosis in breast cancer cells.

MUC16/CA125 is a tumor marker currently used in clinics for the follow-up of patients with ovarian cancer. However, MUC16 expression is not entirely restricted to ovarian malignancies and has been reported in other cancers including breast cancer. Although it is well established as a biomarker, function of MUC16 in cancer remains to be elucidated. In the present study, we investigated the role of MUC16 in breast cancer and its underlying mechanisms. Interestingly, our results showed that MUC16 is overexpressed in breast cancer tissues whereas not expressed in non-neoplastic ducts. Further, stable knockdown of MUC16 in breast cancer cells (MDA MB 231 and HBL100) resulted in significant decrease in the rate of cell growth, tumorigenicity and increased apoptosis. In search of a mechanism for breast cancer cell proliferation we found that MUC16 interacts with the ezrin/radixin/moesin domain-containing protein of Janus kinase (JAK2) as demonstrated by the reciprocal immunoprecipitation method. These interactions mediate phosphorylation of STAT3 (Tyr705), which might be a potential mechanism for MUC16-induced proliferation of breast cancer cells by a subsequent co-transactivation of transcription factor c-Jun. Furthermore, silencing of MUC16 induced G2/M arrest in breast cancer cells through downregulation of Cyclin B1 and decreased phosphorylation of Aurora kinase A. This in turn led to enhanced apoptosis in the MUC16-knockdown breast cancer cells through Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated extrinsic apoptotic pathway with the help of c-Jun N-terminal kinase signaling. Collectively, our results suggest that MUC16 has a dual role in breast cancer cell proliferation by interacting with JAK2 and by inhibiting the apoptotic process through downregulation of TRAIL.

Cannabinoid 1 receptor activation contributes to vascular inflammation and cell death in a mouse model of diabetic retinopathy and a human retinal cell line.

AIMS/HYPOTHESIS: Recent studies have demonstrated that cannabinoid-1 (CB(1)) receptor blockade ameliorated inflammation, endothelial and/or cardiac dysfunction, and cell death in models of nephropathy, atherosclerosis and cardiomyopathy. However the role of CB(1) receptor signalling in diabetic retinopathy remains unexplored. Using genetic deletion or pharmacological inhibition of the CB(1) receptor with SR141716 (rimonabant) in a rodent model of diabetic retinopathy or in human primary retinal endothelial cells (HREC) exposed to high glucose, we explored the role of CB(1) receptors in the pathogenesis of diabetic retinopathy. METHODS: Diabetes was induced using streptozotocin in C57BL/6J Cb(1) (also known as Cnr1)(+/+) and Cb(1)(-/-) mice aged 8 to 12 weeks. Samples from mice retina or HREC were used to determine: (1) apoptosis; (2) activity of nuclear factor kappa B, intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), poly (ADP-ribose) polymerase and caspase-3; (3) content of 3-nitrotyrosine and reactive oxygen species; and (4) activation of p38/Jun N-terminal kinase/mitogen-activated protein kinase (MAPK). RESULTS: Deletion of CB(1) receptor or treatment of diabetic mice with CB(1) receptor antagonist SR141716 prevented retinal cell death. Treatment of diabetic mice or HREC cells exposed to high glucose with SR141716 attenuated the oxidative and nitrative stress, and reduced levels of nuclear factor κB, ICAM-1 and VCAM-1. In addition, SR141716 attenuated the diabetes- or high glucose-induced pro-apoptotic activation of MAPK and retinal vascular cell death. CONCLUSIONS/INTERPRETATION: Activation of CB(1) receptors may play an important role in the pathogenesis of diabetic retinopathy by facilitating MAPK activation, oxidative stress and inflammatory signalling. Conversely, CB(1) receptor inhibition may be beneficial in the treatment of this devastating complication of diabetes.