Vitamin D3 suppresses morphological evolution of the cribriform cancerous phenotype.

Ravi K Deevi,Karen D Mccloskey,Dorota Tkocz,Robyn Higginson,Maurice B Loughrey,Marnix Jansen,Frederick C Campbell,Victoria Marsh Durban,Arman Javadi,Jane Mcclements,Aliya Fatehullah,Alan Clarke

doi:10.18632/oncotarget.8863

Abstract

Development of cribriform morphology (CM) heralds malignant change in human colon but lack of mechanistic understanding hampers preventive therapy. This study investigated CM pathobiology in three-dimensional (3D) Caco-2 culture models of colorectal glandular architecture, assessed translational relevance and tested effects of 1,25(OH)2D3, the active form of vitamin D. CM evolution was driven by oncogenic perturbation of the apical polarity (AP) complex comprising PTEN, CDC42 and PRKCZ (phosphatase and tensin homolog, cell division cycle 42 and protein kinase C zeta). Suppression of AP genes initiated a spatiotemporal cascade of mitotic spindle misorientation, apical membrane misalignment and aberrant epithelial configuration. Collectively, these events promoted “Swiss cheese-like” cribriform morphology (CM) comprising multiple abnormal “back to back” lumens surrounded by atypical stratified epithelium, in 3D colorectal gland models. Intestinal cancer driven purely by PTEN-deficiency in transgenic mice developed CM and in human CRC, CM associated with PTEN and PRKCZ readouts. Treatment of PTEN-deficient 3D cultures with 1,25(OH)2D3 upregulated PTEN, rapidly activated CDC42 and PRKCZ, corrected mitotic spindle alignment and suppressed CM development. Conversely, mutationally-activated KRAS blocked 1,25(OH)2D3 rescue of glandular architecture. We conclude that 1,25(OH)2D3 upregulates AP signalling to reverse CM in a KRAS wild type (wt), clinically predictive CRC model system. Vitamin D could be developed as therapy to suppress inception or progression of a subset of colorectal tumors.

Highlights

Oncogenic perturbation of cell-cell interactions and hierarchical, three-dimensional (3D) tissue organization characterizes cancer development [1] and progression [2]
Rescue of Caco-2 ShPTEN gland morphology by 1,25(OH)2D3 treatment was blocked by PRKCZI treatment (Figure 3F, 3G). These findings show that 1,25(OH)2D3 can rescue aberrant morphology of Caco-2 ShPTEN glands by targeting CDC42/PRKCZ crosstalk
We found that log-transformed PTEN RNAscope values (Supplementary Figure S6B), PTEN IHC and SLC9A3R1 IHC scores all correlated in human colorectal cancer (CRC) (PTEN RNA vs PTEN IHC, r = 0.33; p < 0.01; PTEN RNA vs SLC9A3R1 apical intensity r = 0.36; p < 0.01; PTEN IHC vs SLC9A3R1 apical intensity r = 0.28; p < 0.01 Figure 6B)

Summary

Introduction

Oncogenic perturbation of cell-cell interactions and hierarchical, three-dimensional (3D) tissue organization characterizes cancer development [1] and progression [2]. While CM pathobiology remains unclear, lumen formation and epithelial configuration are governed by mitotic spindle orientation [7, 8]. Spindle alignment is controlled by the apical polarity complex including PTEN, CDC42, PRKC and PARD genes [9, 10]. PTEN is a tumor suppressor that coordinates www.impactjournals.com/oncotarget the CDC42-PRKCZ-PARD complex [11, 12] and regulates spindle orientation in nonpolarized cultured cells [13]. PARD3 directs the orientation of pulling forces linked through GPSM2 to spindle microtubules for appropriate spindle alignment [14]. Perturbation of this machinery drives transition to dysplasia in Drosophila [15] but effects on colorectal glandular architecture remain unclear

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