Poster Presentation 37th Lorne Cancer Conference 2025

Investigating the Role of Calcitonin Receptor Knockout in Cancer Cell Growth, Autophagy and Apoptosis (#145)

Tahereh Gharbi 1 , Joe Ciccotosto 1 , Sebastian Furness 2 , David Hare 1 , Peter Wookey 1
  1. Department of Medicine-Austin, University of Melbourne, Heidelberg, VIC, Australia
  2. School of Biomedical Sciences, University of Queensland, Brisbane, QLD, Australia

Calcitonin (CT) receptor isoforms are widely expressed in mammalian tissues and in various cancer types. They play a significant role in cancer cell survival and proliferation.(1-3) Given their prominence in these processes, its various physiological roles are not fully understood. To improve our understanding the effect of CT receptor knockout on cancer cell growth and programmed cell death were investigated. CRISPR/Cas9 gene editing was used to knock out the CT receptor gene (CALCR), specifically targeting exon 9 in sHela cells, which encodes the first transmembrane domain. Sanger sequencing confirmed the deletion of exon 9 in clone E5. E5 cells displayed distinct morphological changes, slower growth patterns, and elevated cell death. To investigate the changes in the cell cycle, we performed flow cytometric analysis with propidium iodide DNA staining to quantify contributions of G1 and G2/S phases. The results revealed a higher proportion of E5 cells in the G2 phase compared to WT cells, indicating decreased cell proliferation. Autophagy and apoptosis in the E5 cells were also examined using the Operetta high-content system with autophagy-related markers such as LysoTrackerTM Green and CalRexinâ PhrodoTM Red, a novel imaging reagent for autophagy. The results indicated increased cell death in E5 cells compared to WT sHELA cells, and the high fluorescence intensity for both cellular markers suggest the formation of cellular autolysosomes. In conclusion, CT receptor knockout in cancer cells leads to decreased cell proliferation, altered growth patterns and morphological changes, along with increased autophagy and apoptosis. Together, these findings suggest that the CT receptor plays an important role in cancer cell survival. Further research will define the underlying molecular mechanisms of CT receptors in cancer. These studies suggest development of ligands as drugs, targeting inhibition of CT receptor activity, may have therapeutic potential for the treatment of cancers.

  1. 1. Gupta P, Furness SGB, Bittencourt L, Hare DL, Wookey PJ. Building the case for the calcitonin receptor as a viable target for the treatment of glioblastoma. Ther Adv Med Oncol. 2020;12:1758835920978110.
  2. 2. Thomas S, Chigurupati S, Anbalagan M, Shah G. Calcitonin increases tumorigenicity of prostate cancer cells: evidence for the role of protein kinase A and urokinase-type plasminogen receptor. Mol Endocrinol. 2006;20(8):1894-911.
  3. 3. Boot A, Oosting J, de Miranda NF, Zhang Y, Corver WE, van de Water B, et al. Imprinted survival genes preclude loss of heterozygosity of chromosome 7 in cancer cells. J Pathol. 2016;240(1):72-83.