Targeting DNA Repair in Ovarian Cancer Treatment Resistance

Most patients with advanced high-grade serous ovarian cancer (HGSOC) develop recurrent disease within 3 years and succumb to the disease within 5 years. Standard treatment for HGSOC is cytoreductive surgery followed by a combination of platinum (carboplatin or cisplatin) and taxol (paclitaxel) chemotherapies. Although initial recurrences are usually platinum-sensitive, patients eventually develop resistance to platinum-based chemotherapy. Accordingly, one of the major problems in the treatment of HGSOC and disease recurrence is the development of chemotherapy resistance. One of the causes of chemoresistance may be redundancies in the repair pathways involved in the response to DNA damage caused by chemotherapy. These pathways may be acting in parallel, where if the repair pathway that is responsible for triggering cell death after platinum chemotherapy therapy is deficient, an alternative repair pathway compensates and drives cancer cells to repair the damage, leading to chemotherapy resistance. In addition, if the repair pathways are epigenetically inactivated by DNA methylation, cell death may not be triggered, resulting in accumulation of mutations and DNA damage. There are novel and existing therapies that can drive DNA repair pathways towards sensitivity to platinum chemotherapy or targeted therapy, thus enabling treatment-resistant ovarian cancer to overcome chemotherapy resistance.     

Treatment strategies for hypertension in patients with type 1 diabetes

ABSTRACT

Introduction

Type 1 diabetes mellitus (T1DM) is a chronic, autoimmune disease that is characterized by total absence of insulin production. Hypertension is a common comorbidity in T1DM with complex pathophysiology, while it is also a well-recognized risk factor for the development of cardiovascular disease (CVD), as well as other microvascular diabetic complications.     

加兰他敏和石杉碱甲生物合成的研究进展

植物来源的加兰他敏、石杉碱甲等乙酰胆碱酯酶抑制剂(AChEIs)以其高效低毒的优势成为当前临床治疗阿尔茨海默病的主流药物。由于目前加兰他敏、石杉碱甲等AChEIs尚未实现工业规模化合成,故仍主要依赖植物提取。然而,药源植物培育周期长、难度大,药效物质含量低,随着社会需求的急剧攀升,供求矛盾日益突出。开发新替代资源以及利用现代基因工程技术合成加兰他敏、石杉碱甲等AChEIs是缓解当前矛盾的有效途径。对近年来加兰他敏和石杉碱甲生物合成的相关研究进展进行综述,总结了替代资源的开发研究现状,以期为挖掘加兰他敏、石杉碱甲等AChEIs优势新资源及利用代谢工程合成药效物质研究提供参考。     

Benefits versus risk profile of buparlisib for the treatment of breast cancer

Introduction: Activation of phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathways occurs in 70% of breast cancer, including PIK3CA activating mutations, PTEN loss and AKT mutation. It is associated with poor prognosis and resistance to anti-HER2 and endocrine therapy. PI3K inhibitors are promising anticancer targets that can reverse resistance to these therapies. Buparlisib (BKM-120) is an orally active pan-PI3K inhibitor evaluated in different solid tumors as monotherapy or in combination.

Areas covered: This article reviews preclinical data, clinical studies that have evaluated the efficacy and safety profiles of buparlisib as a monotherapy or in combination with targeted therapy (including endocrine and anti-HER2 therapy) or cytotoxics. The authors cover completed and ongoing studies to evaluate the benefit vs risk profile of buparlisib.

Expert opinion: Targeting PI3K showed efficacy in BC. Buparlisib, a pan PI3K inhibitor, presents manageable but not negligible toxicity with an activity/toxicity ratio in favor of the use of emerging second generation, α–selective PI3K inhibitors for ongoing and future trials.     

Hedgehog signaling inhibitors in solid and hematological cancers

BackgroundThe hedgehog signaling pathway is normally tightly regulated. Mutations in hedgehog pathway components may lead to abnormal activation. Aberrantly activated hedgehog signaling plays a major role in the development of solid and hematological cancer. In recent years, inhibitors have been developed that attenuate hedgehog signaling; 2 have been approved for use in basal cell carcinoma (BCC), while others are under development or in clinical trials. The aim of this review is to provide an overview of known hedgehog inhibitors (HHIs) and their potential for the treatment of hematological cancers and solid tumors beyond BCC.DesignPublished literature was searched to identify articles relating to HHIs in noncutaneous cancer. Both preclinical and clinical research articles were included. In addition, relevant clinical trial results were identified from www.clinicaltrials.gov. Information on the pharmacology of HHIs is also included.ResultsHHIs show activity in a variety of solid and hematological cancers. In preclinical studies, HHIs demonstrated efficacy in pancreatic cancer, rhabdomyosarcoma, breast cancer, and acute myeloid leukemia (AML). In clinical studies, HHIs showed activity in medulloblastoma, as well as prostate, pancreatic, and hematological cancers. Current clinical trials testing the efficacy of HHIs are underway for prostate, pancreatic, and breast cancers, as well as multiple myeloma and AML.ConclusionsAs clinical trial results become available, it will be possible to discern which additional tumor types are suited to HHI mono- or combination therapy with other anticancer agents. The latter strategy may be useful for delaying or overcoming drug resistance.     

Discovery of [1,2,3]triazolo[4,5-d]pyrimidine derivatives as highly potent,selective, and cellularly active USP28 inhibitors

Ubiquitin specific peptidase 28 (USP28) is closely associated to the occurrence and development of various malignancies, and thus has been validated as a promising therapeutic target for cancer therapy. To date, only few USP28 inhibitors with moderate inhibitory activity have been reported, highly potent and selective USP28 inhibitors with new chemotypes remain to be discovered for pathologically investigating the roles of deubiquitinase. In this current study, we reported the synthesis and biological evaluation of new [1,2,3]triazolo[4,5-d]pyrimidine derivatives as potent USP28 inhibitors. Especially, compound 19 potently inhibited USP28 (IC₅₀ = 1.10 ± 0.02 μmol/L, K_d = 40 nmol/L), showing selectivity over USP7 and LSD1 (IC₅₀ > 100 μmol/L). Compound 19 was cellularly engaged to USP28 in gastric cancer cells. Compound 19 reversibly bound to USP28 and directly affected its protein levels, thus inhibiting the proliferation, cell cycle at S phase, and epithelial-mesenchymal transition (EMT) progression in gastric cancer cell lines. Docking studies were performed to rationalize the potency of compound 19. Collectively, compound 19 could serve as a new tool compound for the development of new USP28 inhibitors for exploring the roles of deubiquitinase in cancers.     

CDK4/6抑制剂在激素受体阳性进展期乳腺癌治疗中的研究进展

内分泌治疗因其兼具良好的疗效及安全性,是激素受体阳性进展期乳腺癌患者的重要治疗手段。近年来内分泌领域进展迅速,很多新型药物相继出现,其中包括多种可以逆转或延迟内分泌耐药的周期蛋白依赖性激酶(cyclin-dependent kinase,CDK)4/6抑制剂。CDK4/6抑制剂联合内分泌治疗可为激素受体阳性进展期乳腺癌患者带来生存获益、延迟至化疗时间,正逐渐改变国内外激素受体阳性进展期乳腺癌的治疗模式。本文将就CDK4/6抑制剂在激素受体阳性进展期乳腺癌中的治疗进展进行综述。