SOX9 gene shows association with adolescent idiopathic scoliosis predisposition in Northwest Indians.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is a common structural deformity of the spine affecting adolescent individuals globally. The disorder is polygenic and is accompanied by the association of various genetic loci. Genetic studies in Chinese and Japanese populations have shown the association of genetic variants of SOX9 with AIS curve severity. However, no genetic study evaluating the association of SRY-Box Transcription Factor 9 (SOX9) variants with AIS predisposition has been conducted in any Indian population. Thus, we aimed to investigate the association of the genetic variants of the SOX9 along with 0.88 Mb upstream region with AIS susceptibility in the population of Northwest India. METHODS: In total, 113 AIS cases and 500 non-AIS controls were recruited from the population of Northwest India in the study and screened for 155 genetic variants across the SOX9 gene and 0.88 Mb upstream region of the gene using Global Screening Array-24 v3.0 chip (Illumina). The statistical significance of the Bonferroni threshold was set at 0.000322. RESULT: The results showed the association of 11 newly identified variants; rs9302936, rs7210997, rs77736349, rs12940821, rs9302937, rs77447012, rs8071904, rs74898711, rs9900249, rs2430514, and rs1042667 with the AIS susceptibility in the studied population. Only one variant, rs2430514, was inversely associated with AIS in the population, while the ten variants were associated with the AIS risk. Moreover, 47 variants clustered in the gene desert region of the SOX9 gene were associated at a p-value ≤ 0.05. CONCLUSION: The present study is the first to demonstrate the association of SOX9 enhancer locus variants with AIS in any South Asian Indian population. The results are interesting as rs1042667, a 3' untranslated region (UTR) variant in the exon 3 and upstream variants of the SOX9 gene, were associated with AIS susceptibility in the Northwest Indian population. This provides evidence that the variants in the enhancer region of SOX9 might regulate its gene expression, thus leading to AIS pathology and might act as an important gene for AIS susceptibility.

The Second COVID-19 Wave Is a Tsunami With Aftershocks: Mucormycosis Ire as Seen in a Tertiary Care Hospital in Uttarakhand, India.

BACKGROUND: During the spread of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) or the coronavirus disease 2019 (COVID-19) pandemic in recent times, an upsurge of invasive fungal infections (IFIs) such as mucormycosis was witnessed by many countries like India. This COVID-19-associated mucormycosis (CAM) has presented as a menace to the already creaking health infrastructure. Clinical manifestations, risk factors, and end clinical outcomes varied for every other region/country. The aim of this study is to delineate and analyze plausible clinical and epidemiological factors and associated predictors of CAM in suspected patients presenting to a tertiary care hospital in Uttarakhand, India, during the second wave of COVID-19 in India. MATERIAL AND METHODS: A total of 200 cases of suspected post­COVID-19 mucormycosis were enrolled. Data were collected taking into account parameters such as hospitalization and ICU admissions during the episode of COVID-19 infection, steroid/antibiotics/oxygen requirement, and comorbidities such as diabetes mellitus, hypertension, or any chronic illness and outcome. RESULTS: Participants diagnosed with CAM using KOH examination and fungal culture were analyzed in the study (n=46). The median age of patients included was 48, 73.9% were males, and 26% were females. The major predisposing factor was found to be diabetes mellitus type 2. Our work suggests that the mean duration between COVID-19 episodes and CAM was 11.86 days with a significant statistical association. Oxygen requirement and imprudent use of steroids/antibiotics were also allied with mucormycosis. CONCLUSION: The burden of such IFIs is expected to be unveiled in tropical countries during pandemics such as COVID-19, which lead to immunosuppression in masses post-treatment. Comorbidities such as diabetes, chronic kidney disease, and hypertension add to the risk of acquiring other infectious disease. Such times require competent healthcare professionals such as diagnosticians, physicians, and surgeons who are skilled to manage such IFIs timely.

Bacterial Isolates and Their Antimicrobial Susceptibility Profile in Osteomyelitis Patients: An Experience From a Tertiary Care Center in a Hilly Area of Uttarakhand.

Osteomyelitis, an infection related to bone and bone marrow, is very diverse in its pathophysiology and clinical presentation; hence, it is considered one of the most difficult-to-treat infections. The present study is aimed at assessing the microbiological profile of osteomyelitis and related antimicrobial susceptibility patterns in patients attending a tertiary care center in Uttarakhand, India, over a period of one year (January to December 2019). In aerobic culture, 58/105 (55.2%) bacterial isolates were detected. In addition, Staphylococcus aureus was the most common isolate, and amongst Gram-negative bacilli, most isolates that grew on culture were Escherichia coli (22.4%). Out of 21 S. aureus isolates, methicillin resistance was detected in nine [9/21 (42%)] cases, which is a matter of concern. Hence, proper training and application of antimicrobial stewardship are the need of the hour so that clinicians can initiate targeted therapy as early as possible.

Prevalence of Hepatitis B and Hepatitis C in Patients undergoing hemodialysis at a teaching hospital in Uttarakhand.

Introduction: Hemodialysis (HD) requires blood exposure to infectious materials through the extracorporeal circulation for a prolonged period, and exposure to risk factors for nosocomial infections is always there. Aims and Objectives: To determine the prevalence of hepatitis B and hepatitis C in patients undergoing hemodialysis and evaluate the various modes of transmission involved in the causation of the infection. Materials and Methods: A total of 60 patients with chronic kidney disease, admitted to our hospital for HD, were screened for hepatitis B surface antigen (HBsAg) and anti-HCV antibodies. A questionnaire was designed to evaluate risk factors and data were generated to evaluate the significance of the association. Results: Out of 60 subjects, an anti-HCV antibody was detected in 31.68% of patients and 11.66% of patients were positive for HBsAg. The maximum anti-HBV-positive patients were in >60 years of age group (11.53%), whereas the maximum HCV-positive patients were between 41 and 50 age group (23.07%). Most of the HCV-positive patients (54.54%), as well as HBV-positive patients (23.52%), received hemodialysis 50 to 100 times. The major primary disease-causing end-stage renal disease (ESRD) included chronic nephritis (35%). The duration of dialysis, multiple blood transfusions, drug addiction, and body piercing/tattooing were also observed as significant risk factors. Conclusion: In HD patients, viral hepatitis poses a significant health hazard, particularly in developing countries. HBV vaccination, strict adherence to the universal precautions, segregation of HBV-positive patients can control HBV infection in HD units. However, for HCV, the absence of a specific vaccine and the nosocomial transmission of the virus increase the peril more.

The first study of epidemiology of adolescent idiopathic scoliosis shows lower prevalence in females of Jammu and Kashmir, India.

AIS is a heterogeneous 3D spinal deformity with Cobb angle ≥10°. It affects children in the age group of 10-16 years globally with 2-3% prevalence and significant female predominance. The exact etiology of AIS is not known however, it is supposed to be associated with factors such as anthropometric, metabolic, neuromuscular abnormalities and genetics. OBJECTIVES: To determine the prevalence of AIS and association of anthropometric factors with AIS in the studied population group. METHODOLOGY: Scoliosis screening of 9,500 individuals was carried out at different educational institutions of Jammu region in Jammu and Kashmir, India using a scoliosis-meter. The subjects were later examined radiologically. RESULTS: In population of the region, AIS was most prevalent among all types of scoliosis with overall prevalence of 0.61%. The prevalence was observed to be lower in females (0.31%) than males (0.88%). Based on angle of trunk rotation (ATR), lumbar curves were more prevalent than thoracic curves. Average Cobb angle in males and females were 24.9° and 22.6°, respectively. BMI showed significant association with AIS in the age group of 12-16 years (P value =0.028). Furthermore, height was significantly associated with AIS in the overall screened population (P-value =0.029). CONCLUSIONS: The AIS patients in the Jammu region of India have unique clinical features. In contrast to the global prevalence data, the prevalence of AIS in females in the region was less in comparison to males. Based on epidemiological literature and our findings, we hypothesized that genetic factors might be a major contributor in the AIS pathogenesis along with other confounding factors such as height, BMI, ethnicity, etc.

Evaluation of Sphingomonas paucimobilis as an emerging nosocomial pathogen in a teaching hospital in Uttarakhand.

BACKGROUND AND OBJECTIVES: Sphingomonas paucimobilis is an opportunistic pathogen and was rarely encountered in clinical specimens previously. This study aimed to investigate the clinical features, associated co-morbidities, and antimicrobial susceptibility patterns of S. paucimobilis infection in a tertiary hospital in Uttarakhand. MATERIALS AND METHODS: S. paucimobilis isolates cultured from various sections of hospital and OPDs were identified and analyzed for their antibiograms in the microbiology laboratory for a duration of one year from January 2020 to December 2020. RESULTS: S. paucimobilis was isolated from 49 samples (0.01%) out of 3792 samples processed in VITEK 2 Compact automated ID/AST instrument. The maximum number of isolates were obtained from urine samples (31%), followed by blood (24%). Septicemia (41%), meningitis (17%), lower respiratory tract infections and ventilator associated pneumonia (14%) constituted a major portion of infections caused by this organism. Diabetes mellitus (22%) and steroid usage (16%) were major associated co-morbid conditions. Third and Fourth generation cephalosporins like ceftriaxone (81%) and cefepime (86%) were found to be the most susceptible drugs whereas 61% of isolates were resistant to colistin. CONCLUSION: This organism is an up-and-coming pathogen and should not be simply labeled as a contaminant. Although the organism is not grossly virulent and still might not be associated with serious life-threatening infections; however their evolving resistance patterns and increased spectrum of infections should be seriously taken into account.

RETRACTED: A subset of PARP inhibitors induces lethal telomere fusion in ALT-dependent tumor cells.

About 10% of all tumors, including most lower-grade astrocytoma, rely on the alternative lengthening of telomere (ALT) mechanism to resolve telomeric shortening and avoid limitations on their growth. Here, we found that dependence on the ALT mechanism made cells hypersensitive to a subset of poly(ADP-ribose) polymerase inhibitors (PARPi). We found that this hypersensitivity was not associated with PARPi-created genomic DNA damage as in most PARPi-sensitive populations but rather with PARPi-induced telomere fusion. Mechanistically, we determined that PARP1 was recruited to the telomeres of ALT-dependent cells as part of a DNA damage response. By recruiting MRE11 and BRCC3 to stabilize TRF2 at the ends of telomeres, PARP1 blocked chromosomal fusion. Exposure of ALT-dependent tumor cells to a subset of PARPi induced a conformational change in PARP1 that limited binding to MRE11 and BRCC3 and delayed release of the TRF2-mediated block on lethal telomeric fusion. These results therefore provide a basis for PARPi treatment of ALT-dependent tumors, as well as establish chromosome fusion as a biomarker of their activity.

Clinico-epidemiological profile of Influenza A H1N1 cases at a tertiary care institute of Uttarakhand.

INTRODUCTION: The swine (H1N1) virus responsible for worldwide pandemics since 2009 is now causing seasonal epidemics. Since then alarming spikes of swine flu cases have been reported from Uttarakhand every year. There are limited studies conducted in this Himalayan belt to evaluate the clinical and epidemiological profile of the patients admitted in tertiary care hospitals. AIMS & OBJECTIVES: This study aims to summarize the clinical and epidemiological attributes of swine flu and to approximate the burden of Influenza A H1N1 (Swine Flu) cases in this Himalayan belt. MATERIAL AND METHODS: Clinical and epidemiological characteristics of influenza A H1N1 cases from October 2018 to April 2019 were retrospectively and descriptively analyzed using data from the Medical Records Section and the isolation ward at Shri Guru Ram Rai Institute of Medical and Health Sciences; Shri Mahant Indiresh hospital. RESULTS: A total of 1126 (51.6%) patients were tested of which 30% (338) patients were found to be H1N1 positive. Maximum cases and positivity were detected in the months of January (26.4%), February (50.3%), and March (14.8%), and the patients in the age groups of 41-50 (21.9%) and 51-60 years (19.3%) accounted for majority of the cases. The most common symptoms were fever (85.8%), cough (82.2%), sore throat (82%), and breathlessness (71.3%). A case fatality ratio of 10.9% was observed. A significant statistical association (p value < 0.00001) was reported between co-morbid conditions and death. CONCLUSION: According to the results of this study, close caution should be exercised in case of patients infected with H1N1 particularly those with co-morbidities.

Mutant IDH1 Cooperates with ATRX Loss to Drive the Alternative Lengthening of Telomere Phenotype in Glioma.

A subset of tumors use a recombination-based alternative lengthening of telomere (ALT) pathway to resolve telomeric dysfunction in the absence of TERT. Loss-of-function mutations in the chromatin remodeling factor ATRX are associated with ALT but are insufficient to drive the process. Because many ALT tumors express the mutant isocitrate dehydrogenase IDH1 R132H, including all lower grade astrocytomas and secondary glioblastoma, we examined a hypothesized role for IDH1 R132H in driving the ALT phenotype during gliomagenesis. In p53/pRb-deficient human astrocytes, combined deletion of ATRX and expression of mutant IDH1 were sufficient to create tumorigenic cells with ALT characteristics. The telomere capping complex component RAP1 and the nonhomologous DNA end joining repair factor XRCC1 were each downregulated consistently in these tumorigenic cells, where their coordinate reexpression was sufficient to suppress the ALT phenotype. RAP1 or XRCC1 downregulation cooperated with ATRX loss in driving the ALT phenotype. RAP1 silencing caused telomere dysfunction in ATRX-deficient cells, whereas XRCC1 silencing suppressed lethal fusion of dysfunctional telomeres by allowing IDH1-mutant ATRX-deficient cells to use homologous recombination and ALT to resolve telomeric dysfunction and escape cell death. Overall, our studies show how expression of mutant IDH1 initiates telomeric dysfunction and alters DNA repair pathway preferences at telomeres, cooperating with ATRX loss to defeat a key barrier to gliomagenesis.Significance: Studies show how expression of mutant IDH1 initiates telomeric dysfunction and alters DNA repair pathway preferences at telomeres, cooperating with ATRX loss to defeat a key barrier to gliomagenesis and suggesting new therapeutic options to treat low-grade gliomas. Cancer Res; 78(11); 2966-77. ©2018 AACR.

PTEN loss in circulating tumour cells correlates with PTEN loss in fresh tumour tissue from castration-resistant prostate cancer patients.

BACKGROUND: PTEN gene loss occurs frequently in castration-resistant prostate cancer (CRPC) and may drive progression through activation of the PI3K/AKT pathway. Here, we developed a novel CTC-based assay to determine PTEN status and examined the correlation between PTEN status in CTCs and matched tumour tissue samples. METHODS: PTEN gene status in CTCs was evaluated on an enrichment-free platform (Epic Sciences) by fluorescence in situ hybridisation (FISH). PTEN status in archival and fresh tumour tissue was evaluated by FISH and immunohistochemistry. RESULTS: Peripheral blood was collected from 76 patients. Matched archival and fresh cancer tissue was available for 48 patients. PTEN gene status detected in CTCs was concordant with PTEN status in matched fresh tissues and archival tissue in 32 of 38 patients (84%) and 24 of 39 patients (62%), respectively. CTC counts were prognostic (continuous, P=0.001). PTEN loss in CTCs associated with worse survival in univariate analysis (HR 2.05; 95% CI 1.17-3.62; P=0.01) and with high lactate dehydrogenase (LDH) in metastatic CRPC patients. CONCLUSIONS: Our results illustrate the potential use of CTCs as a non-invasive, real-time liquid biopsy to determine PTEN gene status. The prognostic and predictive value of PTEN in CTCs warrants investigation in CRPC clinical trials of PI3K/AKT-targeted therapies.

Biomarker analyses from a placebo-controlled phase II study evaluating erlotinib±onartuzumab in advanced non-small cell lung cancer: MET expression levels are predictive of patient benefit.

PURPOSE: In a recent phase II study of onartuzumab (MetMAb), patients whose non-small cell lung cancer (NSCLC) tissue scored as positive for MET protein by immunohistochemistry (IHC) experienced a significant benefit with onartuzumab plus erlotinib (O+E) versus erlotinib. We describe development and validation of a standardized MET IHC assay and, retrospectively, evaluate multiple biomarkers as predictors of patient benefit. EXPERIMENTAL DESIGN: Biomarkers related to MET and/or EGF receptor (EGFR) signaling were measured by IHC, FISH, quantitative reverse transcription PCR, mutation detection techniques, and ELISA. RESULTS: A positive correlation between IHC, Western blotting, and MET mRNA expression was observed in NSCLC cell lines/tissues. An IHC scoring system of MET expression taking proportional and intensity-based thresholds into consideration was applied in an analysis of the phase II study and resulted in the best differentiation of outcomes. Further analyses revealed a nonsignificant overall survival (OS) improvement with O+E in patients with high MET copy number (mean≥5 copies/cell by FISH); however, benefit was maintained in "MET IHC-positive"/MET FISH-negative patients (HR, 0.37; P=0.01). MET, EGFR, amphiregulin, epiregulin, or HGF mRNA expression did not predict a significant benefit with onartuzumab; a nonsignificant OS improvement was observed in patients with high tumor MET mRNA levels (HR, 0.59; P=0.23). Patients with low baseline plasma hepatocyte growth factor (HGF) exhibited an HR for OS of 0.519 (P=0.09) in favor of onartuzumab treatment. CONCLUSIONS: MET IHC remains the most robust predictor of OS and progression-free survival benefit from O+E relative to all examined exploratory markers.

Chk1 inhibition in p53-deficient cell lines drives rapid chromosome fragmentation followed by caspase-independent cell death.

Activation of Checkpoint kinase 1 (Chk1) following DNA damage mediates cell cycle arrest to prevent cells with damaged DNA from entering mitosis. Here we provide a high-resolution analysis of cells as they undergo S- and G2-checkpoint bypass in response to Chk1 inhibition with the selective Chk1 inhibitor GNE-783. Within 4-8 h of Chk1 inhibition following gemcitabine induced DNA damage, cells with both sub-4N and 4N DNA content prematurely enter mitosis. Coincident with premature transition into mitosis, levels of DNA damage dramatically increase and chromosomes condense and attempt to align along the metaphase plate. Despite an attempt to congress at the metaphase plate, chromosomes rapidly fragment and lose connection to the spindle microtubules. Gemcitabine mediated DNA damage promotes the formation of Rad51 foci; however, while Chk1 inhibition does not disrupt Rad51 foci that are formed in response to gemcitabine, these foci are lost as cells progress into mitosis. Premature entry into mitosis requires the Aurora, Cdk1/2 and Plk1 kinases and even though caspase-2 and -3 are activated upon mitotic exit, they are not required for cell death. Interestingly, p53, but not p21, deficiency enables checkpoint bypass and chemo-potentiation. Finally, we uncover a differential role for the Wee-1 checkpoint kinase in response to DNA damage, as Wee-1, but not Chk1, plays a more prominent role in the maintenance of S- and G2-checkpoints in p53 proficient cells.

Phosphoinositide 3-kinase (PI3K) pathway alterations are associated with histologic subtypes and are predictive of sensitivity to PI3K inhibitors in lung cancer preclinical models.

PURPOSE: Class 1 phosphatidylinositol 3-kinase (PI3K) plays a major role in cell proliferation and survival in a wide variety of human cancers. Here, we investigated biomarker strategies for PI3K pathway inhibitors in non-small-cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: Molecular profiling for candidate PI3K predictive biomarkers was conducted on a collection of NSCLC tumor samples. Assays included comparative genomic hybridization, reverse-transcription polymerase chain reaction gene expression, mutation detection for PIK3CA and other oncogenes, PTEN immunohistochemistry, and FISH for PIK3CA copy number. In addition, a panel of NSCLC cell lines characterized for alterations in the PI3K pathway was screened with PI3K and dual PI3K/mTOR inhibitors to assess the preclinical predictive value of candidate biomarkers. RESULTS: PIK3CA amplification was detected in 37% of squamous tumors and 5% of adenocarcinomas, whereas PIK3CA mutations were found in 9% of squamous and 0% of adenocarcinomas. Total loss of PTEN immunostaining was found in 21% of squamous tumors and 4% of adenocarcinomas. Cell lines harboring pathway alterations (receptor tyrosine kinase activation, PI3K mutation or amplification, and PTEN loss) were exquisitely sensitive to the PI3K inhibitor GDC-0941. A dual PI3K/mTOR inhibitor had broader activity across the cell line panel and in tumor xenografts. The combination of GDC-0941 with paclitaxel, erlotinib, or a mitogen-activated protein-extracellular signal-regulated kinase inhibitor had greater effects on cell viability than PI3K inhibition alone. CONCLUSIONS: Candidate biomarkers for PI3K inhibitors have predictive value in preclinical models and show histology-specific alterations in primary tumors, suggesting that distinct biomarker strategies may be required in squamous compared with nonsquamous NSCLC patient populations.

Evidence for sequenced molecular evolution of IDH1 mutant glioblastoma from a distinct cell of origin.

PURPOSE: Mutation in isocitrate dehydrogenase 1 (IDH1) at R132 (IDH1(R132MUT)) is frequent in low-grade diffuse gliomas and, within glioblastoma (GBM), has been proposed as a marker for GBMs that arise by transformation from lower-grade gliomas, regardless of clinical history. To determine how GBMs arising with IDH1(R132MUT) differ from other GBMs, we undertook a comprehensive comparison of patients presenting clinically with primary GBM as a function of IDH1(R132) mutation status. PATIENTS AND METHODS: In all, 618 treatment-naive primary GBMs and 235 lower-grade diffuse gliomas were sequenced for IDH1(R132) and analyzed for demographic, radiographic, anatomic, histologic, genomic, epigenetic, and transcriptional characteristics. RESULTS: Investigation revealed a constellation of features that distinguishes IDH1(R132MUT) GBMs from other GBMs (including frontal location and lesser extent of contrast enhancement and necrosis), relates them to lower-grade IDH1(R132MUT) gliomas, and supports the concept that IDH1(R132MUT) gliomas arise from a neural precursor population that is spatially and temporally restricted in the brain. The observed patterns of DNA sequence, methylation, and copy number alterations support a model of ordered molecular evolution of IDH1(R132MUT) GBM in which the appearance of mutant IDH1 protein is an initial event, followed by production of p53 mutant protein, and finally by copy number alterations of PTEN and EGFR. CONCLUSION: Although histologically similar, GBMs arising with and without IDH1(R132MUT) appear to represent distinct disease entities that arise from separate cell types of origin as the result of largely nonoverlapping sets of molecular events. Optimal clinical management should account for the distinction between these GBM disease subtypes.

COP1 is a tumour suppressor that causes degradation of ETS transcription factors.

The proto-oncogenes ETV1, ETV4 and ETV5 encode transcription factors in the E26 transformation-specific (ETS) family, which includes the most frequently rearranged and overexpressed genes in prostate cancer. Despite being critical regulators of development, little is known about their post-translational regulation. Here we identify the ubiquitin ligase COP1 (also known as RFWD2) as a tumour suppressor that negatively regulates ETV1, ETV4 and ETV5. ETV1, which is mutated in prostate cancer more often, was degraded after being ubiquitinated by COP1. Truncated ETV1 encoded by prostate cancer translocation TMPRSS2:ETV1 lacks the critical COP1 binding motifs and was 50-fold more stable than wild-type ETV1. Almost all patient translocations render ETV1 insensitive to COP1, implying that this confers a selective advantage to prostate epithelial cells. Indeed, COP1 deficiency in mouse prostate elevated ETV1 and produced increased cell proliferation, hyperplasia, and early prostate intraepithelial neoplasia. Combined loss of COP1 and PTEN enhanced the invasiveness of mouse prostate adenocarcinomas. Finally, rare human prostate cancer samples showed hemizygous loss of the COP1 gene, loss of COP1 protein, and elevated ETV1 protein while lacking a translocation event. These findings identify COP1 as a tumour suppressor whose downregulation promotes prostatic epithelial cell proliferation and tumorigenesis.

CD40 pathway activation status predicts response to CD40 therapy in diffuse large B cell lymphoma.

The primary function of B cells, critical components of the adaptive immune response, is to produce antibodies against foreign antigens, as well as to perform isotype class switching, which changes the heavy chain of an antibody so that it can interact with different repertoires of effector cells. CD40 is a member of the tumor necrosis factor superfamily of cell surface receptors that transmits survival signals to B cells. In contrast, in B cell cancers, stimulation of CD40 signaling results in a heterogeneous response in which cells can sometimes undergo cell death in response to treatment, depending on the system studied. We found an association between sensitivity to CD40 stimulation and mutation of the tumor suppressor p53 in a panel of non-Hodgkin's lymphoma cell lines. Consistent with p53's tumor suppressor role, we found that higher levels of intrinsic DNA damage and increased proliferation rates, as well as higher levels of BCL6, a transcriptional repressor proto-oncogene, were associated with sensitivity to CD40 stimulation. In addition, CD40 treatment-resistant cell lines were sensitized to CD40 stimulation after the introduction of DNA-damaging agents. Using gene expression analysis, we also showed that resistant cell lines exhibited a preexisting activated CD40 pathway and that an mRNA expression signature comprising CD40 target genes predicted sensitivity and resistance to CD40-activating agents in cell lines and mouse xenograft models. Finally, the gene signature predicted tumor shrinkage and progression-free survival in patients with diffuse large B cell lymphoma treated with dacetuzumab, a monoclonal antibody with partial CD40 agonist activity. These data show that CD40 pathway activation status may be useful in predicting the antitumor activity of CD40-stimulating therapeutic drugs.

PPM1H is a p27 phosphatase implicated in trastuzumab resistance.

The HER2 oncogene is overexpressed or amplified in 20% of breast cancers. HER2-positive cancer historically portends a poor prognosis, but the HER2-targeted therapy trastuzumab mitigates this otherwise ominous distinction. Nevertheless, some patients suffer disease recurrence despite trastuzumab, and metastatic disease remains largely incurable due to innate and acquired resistance. Thus, understanding trastuzumab resistance remains an unmet medical need. Through RNA interference screening, we discovered that knockdown of the serine/threonine phosphatase PPM1H confers trastuzumab resistance via reduction in protein levels of the tumor suppressor p27. PPM1H dephosphorylates p27 at threonine 187, thus removing a signal for proteasomal degradation. We further determined that patients whose tumors express low levels of PPM1H trend towards worse clinical outcome on trastuzumab. Identifying PPM1H as a novel p27 phosphatase reveals new insight into how cancer cells destabilize a well-recognized tumor suppressor. Furthermore, low PPM1H expression may identify a subset of HER2-positive tumors that are harder to treat.

Durable complete response of metastatic gastric cancer with anti-Met therapy followed by resistance at recurrence.

UNLABELLED: A 48 year-old female with chemo-refractory metastatic gastric cancer to the liver was treated on a Phase I clinical trial with MetMAb, a monoclonal antibody targeting the Met tyrosine kinase receptor. The primary tumor had high MET gene polysomy and evidence for an autocrine production of HGF, the growth factor ligand of Met. A complete response was obtained lasting two years; the cancer recurred as a peritoneal deposit invading into the transverse colon and a gastrohepatic ligament node. Compassionate use of MetMAb therapy at recurrence achieved a mixed response--a partial response of the two initial lesions, but with development of multiple new foci of carcinomatosis. Tissue and serum studies evaluating the Met signaling pathway did correlate with MetMAb treatment response initially and at the time of recurrence. SIGNIFICANCE: This research brief is the first to describe a durable complete response obtained with a molecularly targeted monoclonal antibody, MetMAb, to the receptor tyrosine kinase, Met, in a patient with chemorefractory metastatic gastric cancer. It is also the first to report biomarkers that predicted therapeutic response to Met inhibition.

Molecular biomarker analyses using circulating tumor cells.

BACKGROUND: Evaluation of cancer biomarkers from blood could significantly enable biomarker assessment by providing a relatively non-invasive source of representative tumor material. Circulating Tumor Cells (CTCs) isolated from blood of metastatic cancer patients hold significant promise in this regard. METHODOLOGY/PRINCIPAL FINDINGS: Using spiked tumor-cells we evaluated CTC capture on different CTC technology platforms, including CellSearch and two biochip platforms, and used the isolated CTCs to develop and optimize assays for molecular characterization of CTCs. We report similar performance for the various platforms tested in capturing CTCs, and find that capture efficiency is dependent on the level of EpCAM expression. We demonstrate that captured CTCs are amenable to biomarker analyses such as HER2 status, qRT-PCR for breast cancer subtype markers, KRAS mutation detection, and EGFR staining by immunofluorescence (IF). We quantify cell surface expression of EGFR in metastatic lung cancer patient samples. In addition, we determined HER2 status by IF and FISH in CTCs from metastatic breast cancer patients. In the majority of patients (89%) we found concordance with HER2 status from patient tumor tissue, though in a subset of patients (11%), HER2 status in CTCs differed from that observed in the primary tumor. Surprisingly, we found CTC counts to be higher in ER+ patients in comparison to HER2+ and triple negative patients, which could be explained by low EpCAM expression and a more mesenchymal phenotype of tumors belonging to the basal-like molecular subtype of breast cancer. CONCLUSIONS/SIGNIFICANCE: Our data suggests that molecular characterization from captured CTCs is possible and can potentially provide real-time information on biomarker status. In this regard, CTCs hold significant promise as a source of tumor material to facilitate clinical biomarker evaluation. However, limitations exist from a purely EpCAM based capture system and addition of antibodies to mesenchymal markers could further improve CTC capture efficiency to enable routine biomarker analysis from CTCs.

The mutation spectrum revealed by paired genome sequences from a lung cancer patient.

Lung cancer is the leading cause of cancer-related mortality worldwide, with non-small-cell lung carcinomas in smokers being the predominant form of the disease. Although previous studies have identified important common somatic mutations in lung cancers, they have primarily focused on a limited set of genes and have thus provided a constrained view of the mutational spectrum. Recent cancer sequencing efforts have used next-generation sequencing technologies to provide a genome-wide view of mutations in leukaemia, breast cancer and cancer cell lines. Here we present the complete sequences of a primary lung tumour (60x coverage) and adjacent normal tissue (46x). Comparing the two genomes, we identify a wide variety of somatic variations, including >50,000 high-confidence single nucleotide variants. We validated 530 somatic single nucleotide variants in this tumour, including one in the KRAS proto-oncogene and 391 others in coding regions, as well as 43 large-scale structural variations. These constitute a large set of new somatic mutations and yield an estimated 17.7 per megabase genome-wide somatic mutation rate. Notably, we observe a distinct pattern of selection against mutations within expressed genes compared to non-expressed genes and in promoter regions up to 5 kilobases upstream of all protein-coding genes. Furthermore, we observe a higher rate of amino acid-changing mutations in kinase genes. We present a comprehensive view of somatic alterations in a single lung tumour, and provide the first evidence, to our knowledge, of distinct selective pressures present within the tumour environment.