Saleh Rachidi

Neutrophil-to-lymphocyte ratio and overall survival in all sites of head and neck squamous cell carcinoma.

Current prognostic criteria are insufficient in predicting outcomes in head and neck cancer, necessitating new, readily available biomarkers.

Molecular Chaperone gp96 Is a Novel Therapeutic Target of Multiple Myeloma

Purpose: gp96 (grp94) is a key downstream chaperone in the endoplasmic reticulum (ER) to mediate unfolded protein response (UPR) and the pathogenesis of multiple myeloma is closely linked to dysregulated UPR. In this study, we aimed to determine the roles of gp96 in the initiation and progression of multiple myeloma in vivo and in vitro. Experimental Design: We generated a mouse model with overexpression of XBP1s and conditional deletion of gp96 in B-cell compartment simultaneously to identify the roles of gp96 in the development of multiple myeloma in vivo. Using a short hairpin RNA (shRNA) system, we silenced gp96 in multiple human multiple myeloma cells and examined the effect of gp96 knockdown on multiple myeloma cells by cell proliferation, cell-cycle analysis, apoptosis assay, immunohistochemistry, and human myeloma xenograft model. The anticancer activity of gp96 selective inhibitor, WS13, was evaluated by apoptosis assay and MTT assay. Results: Genetic deletion of gp96 in XBP1s-Tg mice attenuates multiple myeloma. Silencing of gp96 causes severe compromise in human multiple myeloma cell growth through inhibiting Wnt-LRP-survivin pathway. We also confirmed that knockdown of gp96 decreased human multiple myeloma growth in a murine xenograft model. The targeted gp96 inhibitor induced apoptosis and blocked multiple myeloma cell growth, but did not induce apoptosis in pre-B leukemic cells. We have demonstrated that myeloma growth is dependent on gp96 both genetically and pharmacologically. Conclusions: gp96 is essential for multiple myeloma cell proliferation and survival, suggesting that gp96 is a novel therapeutic target for multiple myeloma. Clin Cancer Res; 19(22); 6242–51. ©2013 AACR.

Immune chaperone gp96 drives the contributions of macrophages to inflammatory colon tumorigenesis

Macrophages are important drivers in the development of inflammation-associated colon cancers, but the mechanistic underpinnings for their contributions are not fully understood. Furthermore, Toll-like receptors have been implicated in colon cancer, but their relevant cellular sites of action are obscure. In this study, we show that the endoplasmic reticulum chaperone gp96 is essential in tumor-associated macrophages (TAM) to license their contributions to inflammatory colon tumorigenesis. Mice where gp96 was genetically deleted in a macrophage-specific manner exhibited reduced colitis and inflammation-associated colon tumorigenesis. Attenuation of colon cancer in these mice correlated strikingly with reduced mutation rates of β-catenin, increased efficiency of the DNA repair machinery, and reduced expression of proinflammatory cytokines, including interleukin (IL)-17 and IL-23 in the tumor microenvironment. The genotoxic nature of TAM-associated inflammation was evident by increased expression of genes in the DNA repair pathway. Our work deepens understanding of how TAM promote oncogenesis by altering the molecular oncogenic program within epithelial cells, and it identifies gp96 as a lynchpin chaperone needed in TAM to license their function and impact on expression of critical inflammatory cytokines in colon tumorigenesis.

Molecular Profiling of Multiple Human Cancers Defines an Inflammatory Cancer-Associated Molecular Pattern and Uncovers KPNA2 as a Uniform Poor Prognostic Cancer Marker

Background Immune evasion is one of the recognized hallmarks of cancer. Inflammatory responses to cancer can also contribute directly to oncogenesis. Since the immune system is hardwired to protect the host, there is a possibility that cancers, regardless of their histological origins, endow themselves with a common and shared inflammatory cancer-associated molecular pattern (iCAMP) to promote oncoinflammation. However, the definition of iCAMP has not been conceptually and experimentally investigated. Methods and Findings Genome-wide cDNA expression data was analyzed for 221 normal and 324 cancer specimens from 7 cancer types: breast, prostate, lung, colon, gastric, oral and pancreatic. A total of 96 inflammatory genes with consistent dysregulation were identified, including 44 up-regulated and 52 down-regulated genes. Protein expression was confirmed by immunohistochemistry for some of these genes. The iCAMP contains proteins whose roles in cancer have been implicated and others which are yet to be appreciated. The clinical significance of many iCAMP genes was confirmed in multiple independent cohorts of colon and ovarian cancer patients. In both cases, better prognosis correlated strongly with high CXCL13 and low level of GREM1, LOX, TNFAIP6, CD36, and EDNRA. An “Inflammatory Gene Integrated Score” was further developed from the combination of 18 iCAMP genes in ovarian cancer, which predicted overall survival. Noticeably, as a selective nuclear import protein whose immuno-regulatory function just begins to emerge, karyopherin alpha 2 (KPNA2) is uniformly up-regulated across cancer types. For the first time, the cancer-specific up-regulation of KPNA2 and its clinical significance were verified by tissue microarray analysis in colon and head-neck cancers. Conclusion This work defines an inflammatory signature shared by seven epithelial cancer types and KPNA2 as a consistently up-regulated protein in cancer. Identification of iCAMP may not only serve as a novel biomarker for prognostication and individualized treatment of cancer, but also have significant biological implications.

Platelets subvert T cell immunity against cancer via GARP-TGFβ axis

T cell immunity against cancer in mice is enhanced with platelet-specific deletion of GARP and by platelet inhibitors. Cancer immunotherapy according to GARP Cancer, like microbes, can adapt to a single therapy, making combination therapies the approach of choice. Complementary therapies that decrease immunosuppression may boost the efficacy of immunotherapies. Now, Rachidi et al. report that targeting platelets improves adoptive T cell therapy of multiple cancers in mice. They found that transforming growth factor β (TGFβ) from platelets decrease T cell function largely through the expression of the TGFβ-docking receptor glycoprotein A repetitions predominant (GARP). These data suggest that combining immunotherapy with platelet inhibitors may be a complementary approach to cancer therapy. Cancer-associated thrombocytosis has long been linked to poor clinical outcome, but the underlying mechanism is enigmatic. We hypothesized that platelets promote malignancy and resistance to therapy by dampening host immunity. We show that genetic targeting of platelets enhances adoptive T cell therapy of cancer. An unbiased biochemical and structural biology approach established transforming growth factor β (TGFβ) and lactate as major platelet-derived soluble factors to obliterate CD4+ and CD8+ T cell functions. Moreover, we found that platelets are the dominant source of functional TGFβ systemically as well as in the tumor microenvironment through constitutive expression of the TGFβ-docking receptor glycoprotein A repetitions predominant (GARP) rather than secretion of TGFβ per se. Platelet-specific deletion of the GARP-encoding gene Lrrc32 blunted TGFβ activity at the tumor site and potentiated protective immunity against both melanoma and colon cancer. Last, this study shows that T cell therapy of cancer can be substantially improved by concurrent treatment with readily available antiplatelet agents. We conclude that platelets constrain T cell immunity through a GARP-TGFβ axis and suggest a combination of immunotherapy and platelet inhibitors as a therapeutic strategy against cancer.

GP96 is a GARP chaperone and controls regulatory T cell functions.

Molecular chaperones control a multitude of cellular functions via folding chaperone-specific client proteins. CD4+FOXP3+ Tregs play key roles in maintaining peripheral tolerance, which is subject to regulation by multiple molecular switches, including mTOR and hypoxia-inducible factor. It is not clear whether GP96 (also known as GRP94), which is a master TLR and integrin chaperone, controls Treg function. Using murine genetic models, we demonstrated that GP96 is required for Treg maintenance and function, as loss of GP96 resulted in instability of the Treg lineage and impairment of suppressive functions in vivo. In the absence of GP96, Tregs were unable to maintain FOXP3 expression levels, resulting in systemic accumulation of pathogenic IFN-γ-producing and IL-17-producing T cells. We determined that GP96 serves as an essential chaperone for the cell-surface protein glycoprotein A repetitions predominant (GARP), which is a docking receptor for latent membrane-associated TGF-β (mLTGF-β). The loss of both GARP and integrins on GP96-deficient Tregs prevented expression of mLTGF-β and resulted in inefficient production of active TGF-β. Our work demonstrates that GP96 regulates multiple facets of Treg biology, thereby placing Treg stability and immunosuppressive functions strategically under the control of a major stress chaperone.

Lower circulating platelet counts and antiplatelet therapy independently predict better outcomes in patients with head and neck squamous cell carcinoma

BackgroundHead and neck squamous cell carcinoma (HNSCC) mortality rates have not shown significant reduction in decades. Platelets are being implicated in having cancer-promoting roles, an observation supported by the adverse outcomes associated with thrombocytosis in many malignancies associated with thrombocytosis. However, the prognostic significance of platelet counts in HNSCC is unknown. Here, we comprehensively investigate the predictive value of platelet counts at diagnosis and post-diagnosis antiplatelet treatment in the overall survival of HNSCC patients.MethodsThe study population consists of 1051 pathologically confirmed HNSCC cases diagnosed between years 2000 and 2012 in a tertiary medical center. Platelet count was investigated as a predictor of survival by fitting Cox Proportional Hazards (CPH) regression models to generate Hazard Ratios (HR) and 95% confidence intervals (CI), while adjusting for age, sex, race, stage, treatment and smoking status. Finally, we evaluated the association between overall survival and antiplatelet medication intake after diagnosis.ResultsMultivariable analysis showed an increased death rate in patients with thromobocytosis [HR 2.37, 95% CI 1.60-3.50)] and high normal platelet counts [HR 2.20, 95% CI 1.58-3.05] compared to the reference middle normal group. Post-diagnosis treatment with antiplatelet medications was inversely associated with death rate [HR 0.76, 95% CI 0.58-0.99].ConclusionsHigher platelet counts were associated with poorer prognosis in HNSCC patients, whereas antiplatelet agents were associated with better prognosis. Antiplatelet agents warrant evaluation in preclinical and clinical settings as a way to improve survival in HNSCC.

The use of novel oral anticoagulants for thromboprophylaxis after elective major orthopedic surgery

Venous thromboembolism is a common cause of morbidity and mortality among patients undergoing elective orthopedic surgery. Due to the high incidence of venous thromboembolism in this setting, perioperative anticoagulation is the recommended approach for thromboprophylaxis. Low molecular weight heparin (LMWH), fondaparinux and warfarin are the agents commonly used for thromboprophylaxis. The well-recognized limitations of warfarin and the inconvenience and discomfort associated with the subcutaneous administration of low molecular weight heparin and fondaparinux inspired intense investigation to develop novel oral anticoagulants (NOACs) with more predictable pharmacokinetics, fewer drug interactions and no need for regular laboratory monitoring. Three NOACs have been demonstrated to be effective for thromboprophylaxis after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in large randomized controlled trials. Here we review the pharmacology of rivaroxaban, dabigatran, and apixaban, summarize the major clinical trials of these agents in thromboprophylaxis after THA and TKA, and discuss the clinical factors to be considered by providers when selecting a NOAC for their patients.

Endoplasmic reticulum heat shock protein gp96 maintains liver homeostasis and promotes hepatocellular carcinogenesis.

BACKGROUND & AIMS gp96, or grp94, is an endoplasmic reticulum (ER)-localized heat shock protein 90 paralog that acts as a protein chaperone and plays an important role for example in ER homeostasis, ER stress, Wnt and integrin signaling, and calcium homeostasis, which are vital processes in oncogenesis. However, the cancer-intrinsic function of gp96 remains controversial. METHODS We studied the roles of gp96 in liver biology in mice via an Albumin promoter-driven Cre recombinase-mediated disruption of gp96 gene, hsp90b1. The impact of gp96 status on hepatic carcinogenesis in response to diethyl-nitrosoamine (DENA) was probed. The roles of gp96 on human hepatocellular carcinoma cells (HCC) were also examined pharmacologically with a targeted gp96 inhibitor. RESULTS We demonstrated that gp96 maintains liver development and hepatocyte function in vivo, and its loss genetically promotes adaptive accumulation of long chain ceramides, accompanied by steatotic regeneration of residual gp96+ hepatocytes. The need for compensatory expansion of gp96+ cells in the gp96- background predisposes mice to develop carcinogen-induced hepatic hyperplasia and cancer from gp96+ but not gp96- hepatocytes. We also found that genetic and pharmacological inhibition of gp96 in human HCCs perturbed multiple growth signals, and attenuated proliferation and expansion. CONCLUSIONS gp96 is a pro-oncogenic chaperone and an attractive therapeutic target for HCC.

Melanotic Neuroectodermal Tumor of Infancy: A Systematic Review.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare tumor, usually diagnosed within the first year of age, with a predilection for the maxilla. Although the tumor is usually benign, its rapidly growing nature and ability to cause major deformities in surrounding structures necessitate early diagnosis and intervention. It is important that medical and dental specialists are prepared to make the diagnosis and proceed with appropriate intervention. The authors performed a systematic review of the 472 reported cases from 1918 through 2013 and provided a comprehensive update on this rare entity that can have devastating effects on young patients. This investigation uncovered age at diagnosis as an important prognostic indicator, because younger age correlated with a higher recurrence rate. The authors also present a case report of a 5-month-old girl diagnosed with MNTI and review her clinical presentation and imaging and histopathologic findings.