REDOX IMAGING OF THE p53-DEPENDENT MITOCHONDRIAL REDOX STATE IN COLON CANCER EX VIVO

The mitochondrial redox state and its heterogeneity of colon cancer at tissue level have not been previously reported.Nor has how p53 regulates mitochondial respi ration been measured at(deep)tissue level,presumably due to the unavailability of the technology that has sufficient spatial resolution and tissue penetration depth.Our prior work demonstrated that the mito-chondrial redox state and its intnatumor heterogeneity is associated with cancer aggressiveness in human melanoma and breast cancer in mouse models,with the more metastatic tumons exhi-bit ing localized negions of more oxidized redox state.Using the Chance redox scanner with an in-plane spatial resolution of 200 pm,we imaged the mitochondrial redox state of the wild-type p53 colon tumors(HCT116 p53 ut)and the p5-deleted colon tumors(HCT116 p53-/-)by cllcting the fuorescence si gnals of nicotinamide adenine dimucleotide(NA DH)and oxidized flavoproteins [Fp,including favin adenine dinucleotide(FAD)]from the mouse xenogmafts snap frozen at low temperature.Our results show that:(1)both tumor lines have significant degree of intratumor heterogeneity of the redox state,typically exhibiting a distinct bi modal distribution that either correlates with the spatial core-rim pattern or the“hot/oold”oxida tion-roduction patches;.(2)the p531-group is significantly more beterogencous in the mitochondrial redox state and has a more oxidized turmor core compared to the p53 wt group when the tunor sizes of the two groups are matched;(3)the tumor size dependence of the redox indices(such as Fp and Fp redox ratio)is significant in the p531-group with the larger ones being more oxidized and more hetero-geneous in their redox state,particularly more oxidized in the tumor central regions;(4)the H&E staining images of tumor soctions grossly correlate with the redox images.The present work is the first to reveal at the submillimeter scale the intratumor heterogeneity pattem of the mitochon-drial redox state in colon cancer and the first to indicate that at tissue level the mitochondial redox state is p53 dependent.The findings should assist in our understanding on colon cancer pa thology and developing new imaging biomarkers for dlinical applications.

帕博利珠单抗联合以铂类为基础的化疗治疗非小细胞肺癌合并稳定性脑转移患者的结局:KEYNOTE-021、-189和-407研究的汇总分析

背景与目的此项探索性分析回顾评价了晚期非小细胞肺癌(non-small cell lung cancer,NSCLC)患者的结局,旨在确定基线时合并脑转移是否会影响一线应用帕博利珠单抗联合化疗(pembrolizumab plus chemotherapy,PC)比对单用化疗的疗效。患者和方法对KEYNOTE-021队列G(非鳞癌)、KEYNOTE-189(非鳞癌)和KEYNOTE-407(鳞癌)三项研究晚期NSCLC患者的数据进行汇总分析。患者接受含铂两药化疗和/或35个周期帕博利珠单抗治疗(每3周200 mg)。所有研究均纳入了经治或初治的稳定性脑转移患者(KEYNOTE-189与KEYNOTE-407研究纳入初治脑转移患者)。经治的脑转移患者已处于病情稳定的状态≥2周(KEYNOTE-021队列G患者≥4周),无新发或脑转移病灶扩大的证据且入组前至少3天以上未使用激素。初治的无症状脑转移患者需定期接受脑部影像学检查。结果共纳入1298例患者,其中171例有基线脑转移,1127例无脑转移。两组的中位随访时间(范围)在数据截止时分别为10.9(0.1-35.1)个月和11.0(0.1-34.9)个月。合并脑转移和无脑转移患者的总生存期[0.48(95%CI:0.32-0.70)和0.63(95%CI:0.53-0.75)]和无进展生存期[0.44(95%CI:0.31-0.62)和0.55(95%CI:0.48-0.63)]的风险比(PC/化疗)相似。合并脑转移的患者中,PC组和单用化疗组患者的中位总生存期分别为18.8个月和7.6个月,中位无进展生存期分别为6.9个月和4.1个月。无论是否合并脑转移,PC组患者的客观缓解率都高于单用化疗组,且缓解持续时间有显著延长。合并脑转移的患者中,PC组与单用化疗组的治疗相关不良事件发生率分别为88.2%和82.8%;而无脑转移的患者中,两组治疗相关不良事件的发生率分别为94.5%和90.6%。结论无论是否合并脑转移,与单用化疗相比,帕博利珠单抗联合以铂类为基础的组织学特异性化疗可改善所有PD-L1亚组的临床结局,其中包括PD-L1肿瘤比例评分<1%的患者,并且在晚期NSCLC患者中安全性良好。该方案是晚期NSCLC初治患者的标准方案,并可用于合并稳定性脑转移的患者。

2003年10个引人关注的肿瘤临床试验

本工作由Pennsylvania大学Abramson癌症中心在2004年1月肿瘤新闻简报中评选而出,其共同特点如下:1.文献的主要来源是2003年度的NEJM(5篇)、ASCO(3篇)、JCO(2篇)。2.各入选文献都是结果有统计学意义的多中心大样本量研究。3.都使肿瘤学家对原来的标准治疗模式重新思考和质疑。4.关心的主要焦点是乳腺癌、结直肠癌、肺癌和白血病。5.显示出对靶向治疗的关注。编译者在此基础上参照原文进行了改写。

Invertebrate Iridovirus Modulation of Apoptosis

Programmed cell death (apoptosis) is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent studies that demonstrate that particles of Invertebrate iridescent virus 6 (IIV-6) (Iridoviridae, genus Iridovirus), or an IIV-6 virion protein extract, are capable of inducing apoptosis in lepidopteran and coleopteran cells, at concentrations 1000-fold lower than that required to shut-off host macromolecular synthesis. Induction of apoptosis depends on endocytosis of one or more heat-sensitive virion component(s). Studies with a JNK inhibitor (SP600125) indicated that the JNK signaling pathway is significantly involved in apoptosis in IIV-6 infections of Choristoneura fumiferana cells. The genome of IIV-6 codes for an inhibitor of apoptosis iap gene (193R) that encodes a protein of 208 aa with 15% identity and 28% similarity in its amino acid sequence to IAP-3 from Cydia pomonella ganulovirus (CpGV). Transcription of IIV-6 iap did not require prior DNA or protein synthesis, indicating that it is an immediate-early class gene. Transient expression and gene knockdown studies have confirmed the functional nature of the IIV-6 iap gene. We present a tentative model for IIV-6 induction and inhibition of apoptosis in insect cells and discuss the potential applications of these findings in insect pest control.

Inhibition of the Renin Angiotensin System during Autologous Stem Cell Transplant Does Not Impact Time to Engraftment

Background: The renin angiotensin system RAS modulates hematopoiesis via local effects in the bone marrow. Angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs) may adversely impact hematopoiesis and time to engraftment in patients undergoing stem cell transplant (SCT). Our study assesses whether the use of ACEi or ARBs delays time to engraftment in patients with multiple myeloma undergoing a melphalan based autologous SCT. Methods: A retrospective review of 58 patients who underwent autologous SCT with a melphalan 200 mg/m2 conditioning regimen for multiple myeloma between January 1 and December 31, 2010 was performed. Results: Of 58 evaluable patients, 47 underwent autologous SCT without an ACEi or ARB (control group), and 11 patients were given ACEi or ARBs (treatment group). Mean time to neutrophil engraftment was 11.5 days in the control group, and 11.3 days in treatment group (p = 0.60). Mean time to platelet engraftment in control group was 13.5 days and 15.1 days in treatment group (p = 0.2). There was no statistically significant difference between groups in time to neutropenic fever and length of hospital stay. Conclusion: Our study demonstrates no significant difference in time to engraftment, incidence of neutropenic fever, or length of hospital stay between patients receiving ACEi or ARBS compared to control subjects. We demonstrate that use of low to moderate dose ACEi or ARB does not lead to prolonged time to engraftment and is safe to use in patients undergoing autologous SCT for multiple myeloma.

Tumor biopsy and patient enrollment in clinical trials for advanced hepatocellular carcinoma

Tumor biopsies may help to reliably distinguish hepatocellular carcinoma(HCC) from other tumors, mostly cholangiocarcinoma as well as to identify the patient populations who most benefit from target-driven HCC treatments, in order to improve the success rate of experimental therapies. Clarifying tumor biology may also lead to identify biomarkers with prognostic role and/or enabling to predict response or resistance to therapies. Recently, clinical trials have more efficiently included biomarker endpoints and increasingly collected tumor tissue from enrolled patients. Due to their frail status and sometimes fast-progressing disease, the performance status of patients with HCC progressing on first-line therapy can deteriorate quickly, preventing their enrollment in clinical trials. However, the challenge of identifying the proper patient at the proper time can be overcome by periodic inter-department meetings involving the key specialists taking care of HCC patients, and solid networks between research centers and referring institutions. An early planned biopsy would also facilitate timely inclusion of patients in biology-driven clinical trials. Ultimately, institution of multidisciplinary teams can optimize treatment choice, biopsy timing, and quick enrollment of patients in clinical trials, before their performance status deteriorates.

Engineered T Cell Therapies from a Drug Development Viewpoint

Cancer is one of the leading causes of death worldwide. Recent advances in cellular therapy have demonstrated that this platform has the potential to give patients with certain cancers a second chance at life. Unlike chemical compounds and proteins, cells are living, self-replicating drugs that can be engineered to possess exquisite specificity. For example, T cells can be genetically modified to express chimeric antigen receptors (CARs), endowing them with the capacity to recognize and kill tumor cells and form a memory pool that is ready to strike back against persisting malignant cells. Anti-CD19 chimeric antigen receptor T cells (CART19s) have demonstrated a remarkable degree of clinical efficacy for certain malignancies. The process of developing CART19 essentially follows the conventional “one gene, one drug, one disease” paradigm derived from Paul Ehrlich’s “magic bullet” concept. With major players within the pharmaceutical industry joining forces to commercialize this new category of “living drugs,” it is useful to use CART19 as an example to examine the similarities and differences in its development, compared with that of a conventional drug. In this way, we can assimilate existing knowledge and identify the most effective approach for advancing similar strategies. This article reviews the use of biomarker-based assays to guide the optimization of CAR constructs, preclinical studies, and the evaluation of clinical efficacy;adverse effects (AEs);and CART19 cellular kinetics. Advanced technologies and computational tools that enable the discovery of optimal targets, novel CAR binding domains, and biomarkers predicting clinical response and AEs are also discussed. We believe that the success of CART19 will lead to the development of other engineered T cell therapies in the same manner that the discovery of arsphenamine initiated the era of synthetic pharmaceuticals.

Doxorubicin-conjugated siRNA lipid nanoparticles for combination cancer therapy

Evasion of apoptosis is a hallmark of cancer,attributed in part to overexpression of the antiapoptotic protein B-cell lymphoma 2(Bcl-2).In a variety of cancer types,including lymphoma,Bcl-2 is overexpressed.Therapeutic targeting of Bcl-2 has demonstrated efficacy in the clinic and is the subject of extensive clinical testing in combination with chemotherapy.Therefore,the development of co-delivery systems for Bcl-2 targeting agents,such as small interfering RNA(siRNA),and chemotherapeutics,such as doxorubicin(DOX),holds promise for enabling combination cancer therapies.Lipid nanoparticles(LNPs)are a clinically advanced nucleic acid delivery system with a compact structure suitable for siRNA encapsulation and delivery.Inspired by ongoing clinical trials of albumin-hitchhiking doxorubicin prodrugs,here we developed a DOX-siRNA co-delivery strategy via conjugation of doxorubicin to the surface of siRNAloaded LNPs.Our optimized LNPs enabled potent knockdown of Bcl-2 and efficient delivery of DOX into the nucleus of Burkitts'lymphoma(Raji)cells,leading to effective inhibition of tumor growth in a mouse model of lymphoma.Based on these results,our LNPs may provide a platform for the co-delivery of various nucleic acids and DOX for the development of new combination cancer therapies.

CHOP THER APY INDUCED MITOCHONDRIAL REDOX STATE ALTERATION IN NON-HODGKIN'S LYMPHOMA XENOGRAFTS

We are interested in investigating whether cancer therapy may alter the mitochondrial redox state in cancer cells to inhibit their growth and survival.The redox state can be imaged by the redox scanner that collects the fuorescence signals from both the oxidized-fAavoproteins(Fp)and the reduced form of nicotinamide adenine dinucleotide(NADH)in snap frozen tissues and has been previously employed to study tumor aggressiveness and treatment responses.Here,with the redox scanner we investigated the effects of chemotherapy on mouse xenografts of a human diffuse large B.cell lymphoma cell line(DLCL2).The mice were treated with CHOP therapy,i.e,cyclophosphamide(C)+hydroxydoxorubicin(H)+Oncovin(O)+prednisone(P)with CHO administration on day 1 and prednisone administration on days 1-5.The Fp content of the treated group was significantly decreased(p=0.033)on day 5,and the mitochondrial redox state of the treated group was slightly more reduced than that of the control group(p=0.048).The decrease of the Fp heterogeneity(measured by the mean st andard deviation)had a border-line statistical significance(p=0.071).The result suggests that the mitochondrial metabolism of lymphoma cells was slightly suppressed and the lymphomas became less aggressive after the CHOP therapy.

Mutations in foregut SOX2^+ cells induce efficient proliferation via CXCR2 pathway

Identification of the precise molecular pathways involved in oncogene-induced transformation may help us gain a better understanding of tumor initiation and promotion. Here, we demonstrate that SOX2^+ foregut epithelial cells are prone to oncogenic transformation upon mutagenic insults, such as Kras^G12D and p53 deletion. GFP-based lineage-tracing experiments indicate that SOX2^+ cells are the cells-of-origin of esophagus and stomach hyperplasia. Our observations indicate distinct roles for oncogenic KRAS mutation and P53 deletion. p53 homozygous deletion is required for the acquisition of an invasive potential, and Kras^G12D expression, but not p53 deletion, suffices for tumor formation. Global gene expression analysis reveals secreting factors upregulated in the hyperplasia induced by oncogenic KRAS and highlights a crucial role for the CXCR2 pathway in driving hyperplasia. Collectively, the array of genetic models presented here demonstrate that stratified epithelial cells are susceptible to oncogenic insults, which may lead to a better understanding of tumor initiation and aid in the design of new cancer therapeutics.