Open Access

High expression of immune checkpoints is associated with the TIL load, mutation rate and patient survival in colorectal cancer

  • Authors:
    • Mara Kitsou
    • Georgios D. Ayiomamitis
    • Apostolos Zaravinos
  • View Affiliations

  • Published online on: May 8, 2020     https://doi.org/10.3892/ijo.2020.5062
  • Pages: 237-248
  • Copyright: © Kitsou et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Abstract

Adoptive cell therapy with the use of tumor-infiltrating lymphocytes (TILs) is a very promising immunotherapeutic approach for the treatment of patients with colorectal cancer (CRC). However, within the tumor microenvironment, co‑inhibitory immune checkpoints can inactivate TILs. The aim of the present study was to examine the association between the TIL load, the mutation rate and the clinical outcome in the immune landscape of patients with CRC. RNA‑seq and whole exome seq data of 453 colon adenocarcinomas (COAD) and rectal adenocarcinomas (READ), along with the TIL load and clinicopathological information of each patient, were extracted from the TCGA GDC Data Portal and analyzed computationally. The expression of immune checkpoint molecules was compared between colon cancer and normal tissue. A total of 9 immune‑related gene signatures were investigated in CRC. Spearman's correlation analysis was performed to examine the correlation between the TIL load with the expression of each immune checkpoint molecule. Indoleamine 2,3‑dioxygenase 1 (IDO1) was found to be significantly overexpressed in CRC, whereas V‑domain Ig suppressor of T cell activation (VISTA) and lymphocyte activating 3 (LAG3) were markedly downregulated. A high expression of cytotoxic T‑lymphocyte‑associated protein 4 (CTLA‑4), IDO1, programmed cell death 1 (PD‑1) and T‑cell immunoreceptor with Ig and ITIM domains (TIGIT), tended to be associated with a better overall survival of the patients. In COAD, the TIL load positively correlated with the expression of adenosine A2A receptor (ADORA2A), CTLA‑4, hepatitis A virus cellular receptor 2 (HAVCR2), lymphocyte activating 3 (LAG3), programmed death‑ligand PD‑L1, PD‑L2, TIGIT and VISTA, whereas in READ, such positive correlations were noted only between the TIL load and LAG3 or PD‑L2. The ‘central memory T‑cell’ and ‘exhausted T‑cell’ gene signatures were significantly lower among the READ tumors. The expression of PD‑1, PD‑L1, PD‑L2, CTLA‑4 and IDO1 was significantly higher among COAD patients with a high mutation rate (>34 mutations/Mb) compared to those with a lower rate. Somatic mutations in PD‑1, PD‑L1, CTLA‑4 and other checkpoint molecules did not seem to affect their expression levels. On the whole, the data of the present study highlight the association of immune checkpoint molecules with the TIL load, patient survival and a high mutation rate in CRC. The data corroborate that patients with colon cancer with higher PD1, PD‑L1/2, CTLA‑4 and IDO1 expression, and a high mutation rate, are the ones who will benefit more from the respective immune checkpoint inhibition therapies.

Related Articles

Journal Cover

July 2020
Volume 57 Issue 1

Print ISSN: 1019-6439
Online ISSN:1791-2423

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
x
APA
Kitsou, M., Ayiomamitis, G.D., & Zaravinos, A. (2020). High expression of immune checkpoints is associated with the TIL load, mutation rate and patient survival in colorectal cancer. International Journal of Oncology, 57, 237-248. https://doi.org/10.3892/ijo.2020.5062
MLA
Kitsou, M., Ayiomamitis, G. D., Zaravinos, A."High expression of immune checkpoints is associated with the TIL load, mutation rate and patient survival in colorectal cancer". International Journal of Oncology 57.1 (2020): 237-248.
Chicago
Kitsou, M., Ayiomamitis, G. D., Zaravinos, A."High expression of immune checkpoints is associated with the TIL load, mutation rate and patient survival in colorectal cancer". International Journal of Oncology 57, no. 1 (2020): 237-248. https://doi.org/10.3892/ijo.2020.5062