Rapalogs induce non-apoptotic,autophagy-dependent cell death in HPV-negative TP53 mutant head and neck squamous cell carcinoma

TP53 is the most frequently mutated gene in head and neck squamous cell carcinoma (HNSCC). Patients with HPV-negative TP53 mutant HNSCC have the worst prognosis, necessitating additional agents for treatment. Since mutant p53 causes sustained activation of the PI3K/AKT/mTOR signaling pathway, we investigated the effect of rapalogs RAD001 and CCI-779 on HPV-negative mutTP53 HNSCC cell lines and xenografts. Rapalogs significantly reduced cell viability and colony formation. Interestingly, rapalogs-induced autophagy with no effect on apoptosis. Pretreatment with autophagy inhibitors, 3-methyladenine (3-MA) and ULK-101 rescued the cell viability by inhibiting rapalog-induced autophagy, suggesting that both RAD001 and CCI-779 induce non-apoptotic autophagy-dependent cell death (ADCD). Moreover, rapalogs upregulated the levels of ULK1 and pULK1 S555 with concomitant downregulation of the mTORC1 pathway. However, pretreatment of cells with rapalogs prevented the ULK-101-mediated inhibition of ULK1 to sustained autophagy, suggesting that rapalogs induce ADCD through the activation of ULK1. To further translate our in vitro studies, we investigated the effect of RAD001 in HPV-negative mutTP53 (HN31 and FaDu) tumor cell xenograft model in nude mice. Mice treated with RAD001 exhibited a significant tumor volume reduction without induction of apoptosis, and with a concomitant increase in autophagy. Further, treatment with RAD001 was associated with a considerable increase in pULK1 S555 and ULK1 levels through the inhibition of mTORC1. 3-MA reversed the effect of RAD001 on FaDu tumor growth suggesting that RAD001 promotes ACDC in HPV-negative mutTP53 xenograft. This is the first report demonstrating that rapalogs promote non-apoptotic ADCD in HPV-negative mutTP53 HNSCC via the ULK1 pathway. Further studies are required to establish the promising role of rapalogs in preventing the regrowth of HPV-negative mutTP53 HNSCC.     

Role of Biomarkers in Prediction of Response to Therapeutics in Metastatic Renal-Cell Carcinoma

Renal-cell carcinoma remains one of the elusive cancers that lacks a biomarker. It is the eighth most commonly diagnosed malignancy in the United States, and the incidence has slowly trended upward. In addition to the increase in newly diagnosed cases, the prevalence and overall survival of individuals with kidney cancer also has increased substantially. This formal review synopsizes the literature regarding the current treatment landscape, the utility of biomarkers in renal-cell carcinoma, and future directions regarding next-generation sequencing of circulating tumor DNA.     

Impact of Addition of Metformin to Abiraterone in Metastatic Castration-Resistant Prostate Cancer Patients With Disease Progressing While Receiving Abiraterone Treatment (MetAb-Pro): Phase 2 Pilot Study

Background

There is evidence linking metformin to improved prostate cancer–related outcomes.

mTOR抑制剂AZD2014对肝癌细胞的增殖抑制作用及其机制研究

目的：初步探讨mTOR抑制剂AZD2014对肝癌细胞的增殖抑制作用及其机制。方法：先采用CCK-8法检测不同浓度的AZD2014（10、100、500、1 000 nmol/L）对肝癌细胞增殖的作用，再分别采用荧光定量PCR和Western blot法检测肝癌细胞中含植物同源结构和环指域泛素样蛋白1（UHRF1）mRNA和蛋白的表达水平。结果：细胞增殖实验结果显示，10、100、500、1 000 nmol/L的AZD2014均可显著抑制肝癌细胞的增殖能力，抑制程度与其浓度呈正相关（P < 0.05）；荧光定量PCR和Western blot检测结果显示，500和1 000 nmol/L的AZD2014可显著降低肝癌细胞内UHRF1 mRNA及蛋白的表达水平。结论：AZD2014可能通过抑制肝癌细胞内UHRF1的表达水平来抑制肝癌细胞的增殖能力。     

骨髓激酶X对宫颈癌细胞增殖的影响及可能的作用机制

目的 探讨骨髓激酶X（bone marrow X-linked kinase，BMX）对人宫颈癌细胞增殖的影响及其可能的作用。方法 收集2013—2017年本院34例正常宫颈、25例原位宫颈癌和52例浸润性宫颈癌的临床标本，采用免疫组织化学方法检测不同标本中BMX的表达。转染BMX-TALEN重组质粒构建敲低BMX表达宫颈癌细胞HeLa-BMX^+/-。宫颈癌细胞HeLa-BMX^+/-和HeLa-野生型细胞分别培养于含抑制剂MK-2206和雷帕霉素完全培养基中，并以培养于含有DMSO培养基的细胞为对照组。采用MTT分析测定细胞活力，Western blot检测BMX、Akt、p-Akt、mTOR和p-mTOR表达。结果 免疫组织化学法检测结果显示，正常宫颈组织、原位宫颈癌组织及浸润性宫颈癌组织BMX阳性率差异有统计学意义（26.5% vs 68.0% vs 88.5%，χ²=34.804，P<0.001），两两比较差异亦有统计学意义（P<0.05）。成功构建低表达BMX宫颈癌细胞HeLa-BMX^+/-。Western blot结果显示，BMX和p-Akt在HeLa-BMX^+/-细胞中的表达低于HeLa-野生型细胞（t=6.282，8.117，P<0.001），总Akt表达水平差异无统计学意义（t=2.035，P=0.126）。与对照组比较，经MK-2206和雷帕霉素处理的HeLa-野生型及BMX+/-细胞中p-Akt和p-mTOR的表达均明显受抑制。结论 BMX可能通过PI3K/Akt/mTOR信号通路促进宫颈癌细胞增殖。     

穴位埋线对肾虚血瘀型子宫内膜异位症患者IL-1β、TNF-α、VEGF和MMP-2水平的影响

目的:基于PI3K/Akt/mTOR信号通路,探讨穴位埋线疗法治疗肾虚血瘀型子宫内膜异位症的临床疗效及对IL-1β、TNF-α、VEGF和MMP-2等相关信号通路下游细胞因子的水平的影响。方法:选取肾虚血瘀型子宫内膜异位症的门诊和住院患者86例,按照随机数字表法随机分为穴位埋线组和西药组,西药组口服孕三烯酮胶囊(内美通),穴位埋线组在西药组的基础上采用穴位埋线进行治疗,治疗3个月后观察两组患者的临床疗效和IL-1β、TNF-α、VEGF、MMP-2等相关信号通路下游细胞因子的水平。结果:治疗后穴位埋线组总有效率93.02%(40/43),西药组总有效率83.72%(36/43),两组比较差异无统计学意义(P>0.05)。治疗3个月后,穴位埋线组和西药组的VAS评分、血清IL-1β、TNF-α、VEGF和MMP-2水平均较治疗前改善(P<0.01),但穴位埋线组较西药组改善更为明显(P<0.05或P<0.01)。治疗过程中,西药组不良反应发生率为18.60%(8/43),穴位埋线组不良反应发生率为4.65%(2/43),两组不良反应发生率比较,差异有统计学意义(P<0.05)。结论:穴位埋线可以显著改善子宫内膜异位症患者的临床症状和体征,并能显著降低孕三烯引起的不良反应,可见穴位埋线疗法可以作用PI3K/Akt/mTOR信号通路,通过改善通路下游的IL-1β、TNF-α、VEGF和MMP-2水平,发挥治疗子宫内膜异位症的作用。     

Epimagnolin targeting on an active pocket of mammalian target of rapamycin suppressed cell transformation and colony growth of lung cancer cells

Mammalian target of rapamycin (mTOR) has a pivotal role in carcinogenesis and cancer cell proliferation in diverse human cancers. In this study, we observed that epimagnolin, a natural compound abundantly found in Shin‐Yi, suppressed cell proliferation by inhibition of epidermal growth factor (EGF)‐induced G1/S cell‐cycle phase transition in JB6 Cl41 cells. Interestingly, epimagnolin suppressed EGF‐induced Akt phosphorylation strongly at Ser473 and weakly at Thr308 without alteration of phosphorylation of MAPK/ERK kinases (MEKs), extracellular signal‐regulated kinase (ERKs), and RSK1, resulting in abrogation of the phosphorylation of GSK3β at Ser9 and p70S6K at Thr389. Moreover, we found that epimagnolin suppressed c‐Jun phosphorylation at Ser63/73, resulting in the inhibition of activator protein 1 (AP‐1) transactivation activity. Computational docking indicated that epimagnolin targeted an active pocket of the mTOR kinase domain by forming three hydrogen bonds and three hydrophobic interactions. The prediction was confirmed by using in vitro kinase and adenosine triphosphate‐bead competition assays. The inhibition of mTOR kinase activity resulted in the suppression of anchorage‐independent cell transformation. Importantly, epimagnolin efficiently suppressed cell proliferation and anchorage‐independent colony growth of H1650 rather than H460 lung cancer cells with dependency of total and phosphorylated protein levels of mTOR and Akt. Inhibitory signaling of epimagnolin on cell proliferation of lung cancer cells was observed mainly in mTOR‐Akt‐p70S6K and mTOR‐Akt‐GSK3β‐AP‐1, which was similar to that shown in JB6 Cl41 cells. Taken together, our results indicate that epimagnolin potentiates as chemopreventive or therapeutic agents by direct active pocket targeting of mTOR kinase, resulting in sensitizing cancer cells harboring enhanced phosphorylation of the mTORC2‐Akt‐p70S6k signaling pathway.