TY - JOUR
T1 - Analysis of oncogenic activities of protein kinase D1 in head and neck squamous cell carcinoma
AU - Zhang, Liyong
AU - Li, Zhihong
AU - Liu, Yehai
AU - Xu, Shuping
AU - Tandon, Manuj
AU - Appelboom, Brittany
AU - Lavalle, Courtney R.
AU - Chiosea, Simion I.
AU - Wang, Lin
AU - Sen, Malabika
AU - Lui, Vivian W.Y.
AU - Grandis, Jennifer R.
AU - Wang, Q. Jane
N1 - Funding Information:
The design, data collection, analysis, and interpretation of this study and the writing of the manuscript were supported by University of Pittsburgh Head & Neck SPORE (P50CA097190) pilot fund (Wang), the National Institutes of Health grants (R01CA129127 and R01CA142580) (Wang), Department of Defense award PC150190 (Wang), National Institutes of Health grants (P50CA097190, R01DE023685, and R35CA231998) (Grandis), and Research Grant Council of Hong Kong (GRF #1711484, #17121616; # 14168571; Theme-based Research: T12-401/13-R; Lui).
Publisher Copyright:
© 2018 The Author(s).
PY - 2018/11/12
Y1 - 2018/11/12
N2 - Background: Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cause of cancer death in the US. The protein kinase D (PKD) family has emerged as a promising target for cancer therapy with PKD1 being most intensively studied; however, its role in HNSCC has not been investigated. Methods: The expression of PKD was evaluated in human HNSCC by quantitative RT-PCR, Western blot and immunohistochemistry. Cell proliferation, wound healing, and matrigel invasion assays were performed upon siRNA-mediated knockdown of PKD1 in HNSCC cells, and subcutaneous xenograft mouse model was established by implantation of the stable doxycycline (Dox)-inducible PKD1 expression cell lines for analysis of tumorigenic activity in vivo. Results: PKD1 was frequently downregulated in HNSCC cell lines at both transcript and protein levels. In human HNSCC tissues, PKD1 was significantly down-regulated in localized tumors and metastases, and in patient-paired tumor tissues as compared to their normal counterparts, which was in part due to epigenetic modification of the PRKD1 gene. The function of PKD1 in HNSCC was analyzed using stable doxycycline-inducible cell lines that express native or constitutive-active PKD1. Upon induction, the rate of proliferation, survival, migration and invasion of HNSCC cells did not differ significantly between the control and PKD1 overexpressing cells in the basal state, and depletion of endogenous PKD1 did not impact the proliferation of HNSCC cells. However, the median growth rate of the subcutaneous HNSCC tumor xenografts over time was elevated with PKD1 induction, and the final tumor weight was significantly increased in Dox-induced vs. the non-induced tumors. Moreover, induced expression of PKD1 promoted bombesin-induced cell proliferation of HNSCC and resulted in sustained ERK1/2 activation in response to gastrin-releasing peptide or bombesin stimulation, suggesting that PKD1 potentiates GRP/bombesin-induced mitogenic response through the activation of ERK1/2 in HSNCC cells. Conclusions: Our study has identified PKD1 as a frequently downregulated gene in HNSCC, and functionally, under certain cellular context, may play a role in GRP/bombesin-induced oncogenesis in HNSCC.
AB - Background: Head and neck squamous cell carcinoma (HNSCC) is the sixth leading cause of cancer death in the US. The protein kinase D (PKD) family has emerged as a promising target for cancer therapy with PKD1 being most intensively studied; however, its role in HNSCC has not been investigated. Methods: The expression of PKD was evaluated in human HNSCC by quantitative RT-PCR, Western blot and immunohistochemistry. Cell proliferation, wound healing, and matrigel invasion assays were performed upon siRNA-mediated knockdown of PKD1 in HNSCC cells, and subcutaneous xenograft mouse model was established by implantation of the stable doxycycline (Dox)-inducible PKD1 expression cell lines for analysis of tumorigenic activity in vivo. Results: PKD1 was frequently downregulated in HNSCC cell lines at both transcript and protein levels. In human HNSCC tissues, PKD1 was significantly down-regulated in localized tumors and metastases, and in patient-paired tumor tissues as compared to their normal counterparts, which was in part due to epigenetic modification of the PRKD1 gene. The function of PKD1 in HNSCC was analyzed using stable doxycycline-inducible cell lines that express native or constitutive-active PKD1. Upon induction, the rate of proliferation, survival, migration and invasion of HNSCC cells did not differ significantly between the control and PKD1 overexpressing cells in the basal state, and depletion of endogenous PKD1 did not impact the proliferation of HNSCC cells. However, the median growth rate of the subcutaneous HNSCC tumor xenografts over time was elevated with PKD1 induction, and the final tumor weight was significantly increased in Dox-induced vs. the non-induced tumors. Moreover, induced expression of PKD1 promoted bombesin-induced cell proliferation of HNSCC and resulted in sustained ERK1/2 activation in response to gastrin-releasing peptide or bombesin stimulation, suggesting that PKD1 potentiates GRP/bombesin-induced mitogenic response through the activation of ERK1/2 in HSNCC cells. Conclusions: Our study has identified PKD1 as a frequently downregulated gene in HNSCC, and functionally, under certain cellular context, may play a role in GRP/bombesin-induced oncogenesis in HNSCC.
KW - GRP/bombesin
KW - Head and neck cancer
KW - PKD1
KW - Proliferation
KW - Tumor growth
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U2 - 10.1186/s12885-018-4965-6
DO - 10.1186/s12885-018-4965-6
M3 - Article
C2 - 30419840
AN - SCOPUS:85056362001
SN - 1471-2407
VL - 18
JO - BMC Cancer
JF - BMC Cancer
IS - 1
M1 - 1107
ER -