Effect of recombinant human interleukin 2 on the growth of a BALB/c sarcoma induced by Moloney murine sarcoma virus

Checkpoints and beyond - Immunotherapy in colorectal cancer

Immunotherapy is the latest revolution in cancer therapy. It continues to show impressive results in malignancies like melanoma and others. At least so far, effects are modest in colorectal cancer (CRC) and only a subset of patients benefits from already approved checkpoint inhibitors. In this review, we discuss major hurdles of immunotherapy like the immunosuppressive niche and low immunogenicity of CRC next to current achievements of checkpoint inhibitors, interleukin treatment and adoptive cell transfer (dendritic cells/cytokine induced killer cells, tumor infiltrating lymphocytes, chimeric antigen receptor cells, T cell receptor transfer) in pre-clinical models and clinical trials. We intensively examine approaches to overcome low immunogenicity by combination of different therapies and address future strategies of therapy as well as the need of predictive factors in this emerging field of precision medicine.

Treatment of chemically induced autochthonous rat mammary and colorectal carcinomas with interleukin-2

The antineoplastic efficacy of human interleukin-2 (IL-2) in autochthonous methylnitrosourea-induced mammary carcinoma and in acetoxymethyl-methyl-nitrosamine-induced colorectal carcinoma of Sprague Dawley rats has been investigated. Under the conditions applied, IL-2 was non-toxic. In the mammary carcinoma IL-2 was therapeutically inactive. In the colorectal carcinoma, 1200 U IL-2/day exhibited significant antitumour activity in established tumours as well as in tumours treated "prophylactically" before their manifestation (P less than 0.05). The effect of IL-2 seemed to be more pronounced when given before manifestation of colorectal tumours (T/C = 8.7% vs 17.8% in established tumours). The differential sensitivity of the autochthonous mammary and colorectal carcinoma may be explained by differences in their proliferation rates and differences in volumes at the beginning of IL-2 therapy. IL-2 seems to be preferentially active in small tumours with a low proliferation rate, a feature typical of colon tumours.