Purpose

Most HER2 positive invasive cancers are either intrinsic non-responsive or develop resistance when treated with 1st line HER2 targeting drugs. Both 1st and 2nd line treatments of HER2 positive cancers are aimed at targeting the HER2 receptor directly, thereby strongly limiting the treatment options of HER2/ErbB2 inhibition resistant invasive cancers.

Methods

We used phenotypic high throughput microscopy screening to identify efficient inhibitors of ErbB2-induced invasion using 1st line HER2 inhibitor trastuzumab- and pertuzumab-resistant, p95-ErbB2 expressing breast cancer cells in conjunction with the Prestwick Chemical Library®. The screening entailed a drug’s ability to inhibit ErbB2-induced, invasion-promoting positioning of lysosomes at the cellular periphery, a phenotype that defines their invasiveness. In addition, we used high throughput microscopy and biochemical assays to assess the effects of the drugs on lysosomal membrane permeabilization (LMP) and autophagy, two features connected to cancer treatment. Using 2nd line HER2 inhibitor lapatinib resistant 3-dimensional model systems, we assessed the effects of the drugs on ErbB2 positive breast cancer spheroids and developed a high-throughput invasion assay for HER2 positive ovarian cancer organoids for further evaluation.

Results

We identified Auranofin, Colchicine, Monensin, Niclosamide, Podophyllotoxin, Quinacrine and Thiostrepton as efficient inhibitors of invasive growth of 2nd line HER2 inhibitor lapatinib resistant breast cancer spheroids and ovarian cancer organoids. We classified these drugs into four groups based on their ability to target lysosomes by inducing autophagy and/or LMP, i.e., drugs inducing early LMP, early autophagy with late LMP, late LMP, or neither.

Conclusions

Our results indicate that targetable lysosome-engaging cellular pathways downstream of ErbB2 contribute to invasion. They support lysosomal trafficking as an attractive target for therapy aiming at preventing the spreading of cancer cells. Since these drugs additionally possess anti-inflammatory activities, they could serve as multipurpose drugs simultaneously targeting infection/inflammation and cancer spreading.

中文翻译：

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鉴定具有抗炎活性的溶酶体靶向药物作为治疗耐药 HER2 阳性癌症的潜在侵袭抑制剂

目的

大多数 HER2 阳性浸润性癌症在使用一线 HER2 靶向药物治疗时要么是固有的无反应性，要么会产生耐药性。HER2 阳性癌症的一线和二线治疗均旨在直接靶向 HER2 受体，从而极大地限制了 HER2/ErbB2 抑制耐药侵袭性癌症的治疗选择。

方法

我们使用表型高通量显微镜筛选，使用一线 HER2 抑制剂曲妥珠单抗和帕妥珠单抗耐药、表达 p95-ErbB2 的乳腺癌细胞与 Prestwick Chemical Library® 一起鉴定 ErbB2 诱导侵袭的有效抑制剂。筛选需要一种药物能够抑制 ErbB2 诱导的、促进侵袭的溶酶体在细胞外围的定位，这是一种定义其侵袭性的表型。此外，我们使用高通量显微镜和生化分析来评估药物对溶酶体膜通透性 (LMP) 和自噬的影响，这两个特征与癌症治疗有关。使用二线 HER2 抑制剂拉帕替尼耐药 3 维模型系统，

结果

我们确定了金诺芬、秋水仙碱、莫能菌素、氯硝柳胺、鬼臼毒素、奎纳克林和硫链菌肽作为二线 HER2 抑制剂拉帕替尼耐药乳腺癌球体和卵巢癌类器官侵袭性生长的有效抑制剂。我们根据它们通过诱导自噬和/或 LMP 靶向溶酶体的能力将这些药物分为四组，即诱导早期 LMP 的药物、具有晚期 LMP 的早期自噬、晚期 LMP 或两者都没有的药物。

结论

我们的结果表明，ErbB2 下游的可靶向溶酶体参与细胞通路有助于入侵。他们支持将溶酶体运输作为旨在防止癌细胞扩散的治疗的有吸引力的目标。由于这些药物还具有抗炎活性，因此它们可以作为多用途药物同时针对感染/炎症和癌症扩散。