Physical Poster + E-Poster Presentation 34th Lorne Cancer Conference 2022

Does knocking-out a tetraspanin gene in cancer cells affect the expression of other tetraspanins? (#121)

Rocky Chowdhury 1 2 , Shweta Patel 1 2 , Tuong Nguyen 1 2 , Cuong Pham 1 2 , Phuong Tran 1 2 , Wei Duan 1 2
  1. School of Medicine, Deakin University, Geelong, Victoria, Australia
  2. Institute of Mental and Physical Health and Clinical Translation (IMPACT), Deakin University, Geelong, Victoria, Australia

Tetraspanins are a family of membrane proteins found in all multicellular eukaryotes [1]. They have been discovered to regulate tumor growth, cell adhesion, invasion, and migration in several studies [2]. Importantly, in preclinical models, monoclonal antibodies targeting various tetraspanins result in enhanced cell death and decreased metastasis [3]. Also, tetraspanins are enriched in exosome membranes and are frequently utilized as exosome markers [4]. Thus, tetraspanins could be explored as targets for early-stage cancer diagnostics and therapeutics. In this work, we have investigated the difference between the expression of two tetraspanins (CD63 and CD81) in wild-type (WT) and gene knock-out (KO) versions of human epithelial breast cancer cell line MDA-MB-231 after knocking out a gene for another tetraspanin marker (CD9) using CRISPR-Cas9 technique. After knocking out the tetraspanin CD9 gene, the expression of these tetraspanins was analyzed using flow cytometric analysis. We observed that knocking out the CD9 gene impacted the expression of CD63 differently in different KO clones where for one clone, the expression of CD63 was 1.87-fold higher, and the other clone had a 1.44-fold lower expression of CD63 than that in the WT MDA-MB-231. On the other hand, knocking out the CD9 gene in MDA-MB-231 resulted in a decreased expression of CD81 in both KO clones (1.41-fold and 1.75-fold). These observations suggest that knocking out the gene of one tetraspanin may affect the expression of other tetraspanin proteins in the cancer cells. Further studies will provide insight into the mechanisms underlying the dynamic interactions among different members of tetraspanins.

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