ABSTRACT

Prostate cancer is one of the most common cancer for men worldwide with advanced forms showing supernumerary or clustered centrosomes. Hematological and neurological expressed 1 (HN1) also known as Jupiter Microtubule Associated Homolog 1 (JPT1) belongs to a small poorly understood family of genes that are evolutionarily conserved across vertebrate species. The co-expression network of HN1 from the TCGA PRAD dataset indicates the putative role of HN1 in centrosome-related processes in the context of prostate cancer. HN1 expression is low in normal RWPE-1 cells as compared to cancerous androgen-responsive LNCaP and androgen insensitive PC-3 cells. HN1 overexpression resulted in differential response for cell proliferation and cell cycle changes in RWPE-1, LNCaP, and PC-3 cells. Since HN1 overexpression increased the proliferation rate in PC-3 cells, these cells were used for functional characterization of HN1 in advanced prostate carcinogenesis. Furthermore, alterations in HN expression led to an increase in abnormal to normal nuclei ratio and increased chromosomal aberrations in PC-3 cells. We observed the co-localization of HN1 with γ-tubulin foci in prostate cancer cells, further validated by immunoprecipitation. HN1 was observed as physically associated with γ-tubulin and its depletion led to increased γ-tubulin foci and disruption in microtubule spindle assembly. Higher HN1 expression was correlated with prostate cancer as compared to normal tissues. The restoration of HN1 expression after silencing suggested that it has a role in centrosome clustering, implicating a potential role of HN1 in cell division as well as in prostate carcinogenesis warranting further studies.

摘要

前列腺癌是全世界男性最常见的癌症之一，其晚期形式显示出多余的或聚集的中心体。血液学和神经学表达 1 ( HN1 ) 也称为木星微管相关同源物 1 ( JPT1) 属于一个知之甚少的基因家族，这些基因在脊椎动物物种中是进化上保守的。来自 TCGA PRAD 数据集的 HN1 的共表达网络表明 HN1 在前列腺癌背景下中心体相关过程中的推定作用。与癌性雄激素反应性 LNCaP 和雄激素不敏感的 PC-3 细胞相比，正常 RWPE-1 细胞中的 HN1 表达较低。HN1 过表达导致 RWPE-1、LNCaP 和 PC-3 细胞对细胞增殖和细胞周期变化的不同反应。由于 HN1 过表达增加了 PC-3 细胞的增殖率，因此这些细胞被用于 HN1 在晚期前列腺癌发生中的功能表征。此外，HN的变化表达导致 PC-3 细胞中异常与正常细胞核比率的增加和染色体畸变的增加。我们观察到 HN1 与 γ-微管蛋白灶在前列腺癌细胞中的共定位，通过免疫沉淀进一步验证。观察到 HN1 与 γ-微管蛋白物理相关，其消耗导致 γ-微管蛋白病灶增加和微管纺锤体组装中断。与正常组织相比，较高的 HN1 表达与前列腺癌相关。沉默后 HN1 表达的恢复表明它在中心体聚集中起作用，暗示 HN1 在细胞分裂和前列腺癌发生中的潜在作用值得进一步研究。