夜读札记（六）

一、与CD8 + T细胞耗竭相关的治疗靶点

《Novel targets for immunotherapy associated with exhausted CD8 + T cells in cancer》

In response to prolonged stimulation by tumour antigens, T cells gradually become exhausted. There is growing evidence that exhausted T cells not only lose their potent effector functions but also express multiple inhibitory receptors. Checkpoint blockade (CPB) therapy can improve cancer by reactivating exhausted effector cell function, leading to durable clinical responses, but further improvements are needed given the limited number of patients who benefit from treatment, even with autoimmune complications. Here, we suggest, based on recent advances that tumour antigens are the primary culprits of exhaustion, followed by some immune cells and cytokines that also play an accomplice role in the exhaustion process, and we also propose that chronic stress-induced hypoxia and hormones also play an important role in promoting T-cell exhaustion. Understanding the classification of exhausted CD8+ T-cell subpopulations and their functions is important for the effectiveness of immune checkpoint blockade therapies. We mapped the differentiation of T-cell exhausted subpopulations by changes in transcription factors, indicating that T-cell exhaustion is a dynamic developmental process. Finally, we summarized the novel immune checkpoints associated with depletion in recent years and combined them with bioinformatics to construct a web of exhaustion-related immune checkpoints with the aim of finding novel therapeutic targets associated with T-cell exhaustion in malignant tumours, aiming to revive the killing ability of exhausted T cells and restore anti-tumour immunity through combined targeted immunotherapy.

1、PD-1

2、Siglec15

3、SLAMF6

4、NRP1

5、DUSP2

6、Ptpn2

7、PTPN6


二、伊立替康、阿的平、 阿呋唑嗪是her2抑制剂的替代药物

《Repurposing FDA Drug Compounds against Breast Cancer by Targeting EGFR/HER2》

Repurposing studies have identified several FDA-approved compounds as potential inhibitors of the intracellular domain of epidermal growth factor receptor 1 (EGFR) and human epidermal receptor 2 (HER2). EGFR and HER2 represent important targets for the design of new drugs against different types of cancer, and recently, differences in affinity depending on active or inactive states of EGFR or HER2 have been identified. In this study, we first identified FDA-approved compounds with similar structures in the DrugBank to lapatinib and gefitinib, two known inhibitors of EGFR and HER2. The selected compounds were submitted to docking and molecular dynamics MD simulations with the molecular mechanics generalized Born surface area approach to discover the conformational and thermodynamic basis for the recognition of these compounds on EGFR and HER2. These theoretical studies showed that compounds reached the ligand-binding site of EGFR and HER2, and some of the repurposed compounds did not interact with residues involved in drug resistance. An in vitro assay performed on two different breast cancer cell lines, MCF-7, and MDA-MB-23, showed growth inhibitory activity for these repurposed compounds on tumorigenic cells at micromolar concentrations. These repurposed compounds open up the possibility of generating new anticancer treatments by targeting HER2 and EGFR.

这篇论文 从靶点蛋白结构与药物分子对接的角度，研究了一些替代药物对 乳腺癌 her2、egfr靶点的作用。论文选取的专门的靶向药对照药物是常见的her2的拉帕替尼和egfr的吉非替尼。

化疗药 伊立替康与 her2 的结合亲和力是 56.4±5千卡/摩尔

quinacrine （阿的平，一种老的治疗疟疾的药）与 her2的结合亲和力是 54.9±3千卡/摩尔

两者均高于 her2专门的靶向药拉帕替尼与 her2的结合亲和力 51±4千卡/摩尔

伊立替康常见靶点是top1，从这个研究来看，实际上her2也是伊立替康的治疗靶点。伊立替康与her2的结合亲和力高于拉帕替尼，伊立替康是静脉注射药生物利用度肯定也不会比口服的拉帕替尼差（伊立替康目前还有生物利用度更高的脂质体剂型）。

举轻以明重。

her2扩增her2高表达的乳腺癌患者，可以考虑把伊立替康当her2靶向药用。当然，用伊立替康，还要看UGT1A1基因的突变情况，看看毒副作用是不是大；伊立替康的延迟性腹泻还是很致命的。伊立替康分子量586.69，稍微大了一点，比较可惜。

Alfuzosin 阿呋唑嗪（一种治疗高血压和前列腺增生的药）与her2的结合亲和力 是 51.9±6千卡/摩尔。阿的平与阿呋唑嗪也能作为her2靶向药的替代药物来用。阿呋唑嗪分子量389，比较小，入脑效果应该不错。不过要注意血压降低的风险。



三、Echinacoside、Isoacteoside 对p110α 的结合亲和力超过阿佩利斯

《In-silico prediction of potential inhibitors against phosphatidylinositol 3-kinase catalytic subunit alpha involved in head and neck squamous cell carcinomas》

Head and neck squamous cell carcinoma (HNSCC) is one of the most common cancers, globally. Its high mortality rates remained unaltered in the last three decades, therefore, there is an enormous need for novel therapeutics. The most frequent somatically mutated oncogenic pathway in HNSCC tumors is the Phosphatidylinositol-3-kinases (PI3K) pathway. PI3Ks are lipid kinases involved in the regulation of cell survival, growth and metabolism. PI3Ks phosphorylates PI (4,5) P2 (PIP2) converting it to PI (3, 4, 5) P3 (PIP3). Alterations such as mutation, gene amplification and overexpression in PIK3CA, encoding the catalytic subunit p110α of PI3K pathway were found to be prevalent. The aberrant activation leads to irregulated cell growth due to improper p110α enzymatic activity. p110α is therefore, considered a potential oncogenic target for cancer therapy. The only FDA approved specific inhibitor of p110α is Alpelisib (BYL719). Therefore, designing more effective and specific p110α inhibitors could be a promising strategy in the treatment of HNSCC. The present study aims to find out the potent and novel inhibitors of p110α using High Throughput Screening (HTS) of huge databases (National Cancer Institute (NCI), Life Chemicals, ChemDiv and ChEMBL) and Molecular Dynamic Simulations. As a result, from more than 400,000 compounds, a total of 3 best candidate compounds (Echinacoside, Isoacteoside, K284-4402) were selected and validated for their binding to catalytic site of p110α and stability during Molecular Dynamics (MD) simulations. The binding free energy (calculated from MM-PBSA) of the selected compounds, Echinacoside, Isoacteoside, K284-4402 were -23.43 kcal/mol, -33.02 kcal/mol and -30.57 kcal/mol, respectively, which suggested these compounds bind to p110α with higher affinity than Alpelisib which has binding free energy -20.9 kcal/mol. This study provides a significant in-depth understanding of p110α inhibitors that can be used in the development of potential therapeutics against HNSCC。

阿佩利斯 对 p110α 的结合亲和力是 20.9 kcal/mol

Echinacoside 对 p110α 的结合亲和力是 23.43 kcal/mol

Isoacteoside 对 p110α 的结合亲和力是 33.02 kcal/mol

两者对 p110α 的结合亲和力高于阿佩利斯

这篇论文的结论跟其他一些论文可以相互印证

比如 《Echinacoside inhibits the proliferation, migration, invasion and angiogenesis of ovarian cancer cells through PI3K/AKT pathway》、《Suppression of in vitro and in vivo human ovarian cancer growth by isoacteoside is mediated via sub-G1 cell cycle arrest, ROS generation, and modulation of AKT/PI3K/m-TOR signalling pathway》。

《Echinacoside inhibits colorectal cancer metastasis via modulating gut microbiota and suppressing PI3K/AKT signaling pathway》 这篇论文里有动物试验口服剂量，三个剂量动物体内肿瘤都缩小了。


四、阿托伐醌的抗癌剂量在说明书驱虫常规剂量范围内

阿托伐醌是一种驱虫药，现在研究它有很多抗癌靶点，比如stat3、her2、β-Catenin、肿瘤干细胞等等。

有抗癌靶点的替代药物很多，但是大部分并不实用，主要原因之一就在于 动物模型试验里，肿瘤缩小所需要的替代药物的剂量，远远超过替代药物目前适应症的常规剂量，有时候是几十倍几百倍之多。有时候是人体上根本达不到这个剂量，毒副作用太大；有时候是不清楚能不能达到这个剂量，因为没有人真这么去试过。

而阿托伐醌是极其少见的，动物模型试验里缩瘤所需的剂量，换算成人体剂量后，远远低于阿托伐醌目前适应症正常剂量的替代药物。

这才有了实际使用的可能性。

《Atovaquone: An Antiprotozoal Drug Suppresses Primary and Resistant Breast Tumor Growth by Inhibiting HER2/β-Catenin Signaling》

“Breast cancer is the second leading cause of cancer-related mortality in women. In the current study, we evaluated the anticancer effects of an antiprotozoal drug, atovaquone, against several breast cancer cell lines. Our results showed that atovaquone treatment induced apoptosis and inhibited the growth of all the breast cancer cell lines tested, including several patient-derived cells. In addition, atovaquone treatment significantly reduced the expression of HER2, β-catenin, and its downstream molecules such as pGSK-3β, TCF-4, cyclin D1, and c-Myc in vitro Efficacy of atovaquone was further evaluated in an in vivo tumor model by orthotropic implantation of two highly aggressive 4T1 and CI66 breast cancer cells in the mammary fat pad of female mice. Our results demonstrated that oral administration of atovaquone suppressed the growth of CI66 and 4T1 tumors by 70% and 60%, respectively. Paclitaxel is the first-line chemotherapeutic agent for metastatic breast cancer. We demonstrate that atovaquone administration suppressed the growth of 4T1 paclitaxel-resistant tumors by 40%. Tumors from atovaquone-treated mice exhibited reduced HER2, β-catenin, and c-Myc levels alongside an increase in apoptosis in all the three tumor models when analyzed by Western blotting, IHC, and TUNEL assay. Taken together, our results indicate that atovaquone effectively reduces the growth of primary and paclitaxel-resistant breast tumors. Atovaquone is already in the clinics with high safety and tolerability profile. Therefore, the findings from our studies will potentially prompt further clinical investigation into repurposing atovaquone for the treatment of patients with advanced breast cancer.”

这篇论文里阿托伐醌的动物剂量，换算成人体剂量后是 每天每公斤2.5毫克。一个人体重60公斤的患者，一天剂量是150毫克。一个体重100公斤的患者（在中国200斤的肿瘤患者尤其是乳腺癌女患者应该是万里挑一的），一天剂量也只有250毫克。

阿托伐醌 治疗艾滋病患者卡式肺炎的说明书剂量是“750mg/次，3次/天，与食物同服，共21天。”

即便考虑到用作抗癌使用时间肯定不止21天有毒副作用积累的问题，阿托伐醌的抗癌剂量也是很低的，跟目前适应症说明书剂量仍然有很大的差距，有很大的实用性。

这篇论文的结论跟其他研究论文是可以相互印证的。

《Proguanil and atovaquone use is associated with lower colorectal cancer risk: a nationwide cohort study》

Methods: By accessing a couple of nationwide Swedish registers, we performed a cohort study to explore whether using proguanil and atovaquone might associate with a lower risk of CRC by adopting a new-user study design. Adults who have 1 or more first-degree relatives (parents or siblings) diagnosed with CRC were identified and linked with the Prescribed Drug Register to evaluate their administration history of proguanil and atovaquone. Survival analysis of the time to CRC diagnosis with Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).
Results: A total of 16,817 incident proguanil/atovaquone users were identified and matched with 168,170 comparisons, who did not use proguanil/atovaquone, on the ratio of 1:10. We found a significant negative association between proguanil/atovaquone use and risk of CRC (adjusted HR, 0.76; 95% CI, 0.62-0.93). Test for trend showed significant dose- and duration-response correlations (P < 0.001). The association was more pronounced in CRC diagnosed at an advanced stage than at an early stage (adjusted HR, 0.69 vs.0.81).
Conclusions: This national-wide population-based cohort study showed that the use of proguanil and atovaquone was associated with a reduced risk of CRC among individuals with a family history of CRC.

这篇论文讲了瑞典的一个回顾性研究，有肠癌家族病史的人，用过阿托伐醌的人，得肠癌的风险远远小于没有用过阿托伐醌的人；而且这与用阿托伐醌的剂量和时间显著相关。

肠癌出现频率最高的突变是apc突变，apc基因叫大肠腺癌息肉病基因，这个突变是有一定遗传性的。之前我讲过很多次，apc突变目前没有上市的靶向药，目前治疗策略都是抑制 β-Catenin。而上一篇论文讲阿托伐醌能抑制β-Catenin，两篇论文是相互呼应，相互印证的。

阿托伐醌的分子量366.84  ，比较小，入脑很好。所以现在有临床研究在做阿托伐醌作为脑放疗的增敏增效剂。