Mull Brittany, Davis Ryan, Munir Iqbal, Perez Mia C, Simental Alfred A, Khan Salma
Harbor UCLA Medical Center, Torrance, CA 90502, USA.
Division of Biochemistry, Loma Linda, CA 92350, USA.
Oncotarget. 2021 Mar 30;12(7):596-607. doi: 10.18632/oncotarget.27920.
Thyroid cancer incidence, recurrence, and death rates are higher among Filipino Americans than European Americans. We propose that vitamin D binding protein (DBP) with multifunctionality with ethnic variability plays a key role within different ethnicities. In this study, we determined the correlation between differential DBP expression in tumor tissues and cancer staging in Filipino Americans versus European Americans. We assayed DBP expression by immunohistochemistry and analyzed the data with confocal microscopy on 200 thyroid cancer archival tissue samples obtained from both ethnicities. DBP-stable knockdown/gain-in-function assays were done by using DBP-shRNA/DBP-cDNA-expression . The majority of Filipino Americans presented with advanced tumor staging. In contrast, European Americans showed early staging and very few advanced tumors. A significantly low to no DBP staining was detected and correlated to the advanced staging in Filipino Americans. On the contrary, in the tumor tissues derived from European Americans, moderate to strong DBP staining was detected and correlated to early staging. When downregulation of the DBP gene in papillary thyroid cancer (PTC) cell lines was observed, tumor proliferation and migration were enhanced. On the other hand, the upregulation of the DBP gene decreased cell proliferation and migration in PTC cells. In conclusion, we determined a differential expression of an essential biological molecule (DBP) is linked to cancer staging in thyroid cancer health disparities in two ethnicities. Loss-of-DBP/gain-in-DBP-function influenced tumor progression. A future study is underway to determine the DBP regulation and its downstream pathways to elucidate strategies to eliminate the observed thyroid cancer health disparities.
菲律宾裔美国人的甲状腺癌发病率、复发率和死亡率高于欧裔美国人。我们提出,具有种族变异性且具备多种功能的维生素D结合蛋白(DBP)在不同种族中起着关键作用。在本研究中,我们确定了菲律宾裔美国人和欧裔美国人肿瘤组织中DBP差异表达与癌症分期之间的相关性。我们通过免疫组织化学检测DBP表达,并使用共聚焦显微镜对从这两个种族获得的200份甲状腺癌存档组织样本进行数据分析。通过使用DBP-shRNA/DBP-cDNA表达进行DBP稳定敲低/功能获得实验。大多数菲律宾裔美国人表现为肿瘤晚期。相比之下,欧裔美国人表现为早期分期,晚期肿瘤很少。在菲律宾裔美国人中检测到显著低至无DBP染色,且与晚期分期相关。相反,在欧裔美国人的肿瘤组织中,检测到中度至强DBP染色,且与早期分期相关。当观察到甲状腺乳头状癌(PTC)细胞系中DBP基因下调时,肿瘤增殖和迁移增强。另一方面,DBP基因上调会降低PTC细胞的增殖和迁移。总之,我们确定了一种重要生物分子(DBP)的差异表达与两个种族甲状腺癌健康差异中的癌症分期有关。DBP功能丧失/获得影响肿瘤进展。目前正在进行一项未来研究,以确定DBP调控及其下游途径,从而阐明消除观察到的甲状腺癌健康差异的策略。