gene-editing MC38 cell line：study the Nobel Prize with Nobel Prize

 

Background

MC38 cell line was derived from the colon adenocarcinoma cell line of C57BL/6 mice, which is adherent growth and fibroblast morphology. MC38 cell line implanted into C57BL/6 mice or mice with the low immune function will form tumors and metastases, which are mostly used to study the occurrence and metastasis of colorectal cancer and become a common way to verify the efficacy of tumors^[1]. At present, the commonly used cell models are lentivirus-mediated stable cell line models and CRISPR/Cas9 mediated gene-editing models. Ubigene has been committed to stable cell line generation and gene-editing cell line generation. Ubigene has successfully modified genes from more than 100 cell lines, including the MC38 cell line. We are providing services all over the world. For more details, please inquire>>

MC38 cell line and CRISPR/Cas9 technology can assist tumor immunotherapy

As the Nobel Laureate in 2020, CRISPR/Cas9 technology has already been used in many biological and medical fields. The combination of CRISPR/Cas9 technology and the Nobel Laureate in 2018 "tumor immunotherapy" brings more hope for tumor treatment.

The key gene for validation, which is expected to find new therapeutic targets for colon cancer

Sialylated glycan structures are known for their immunomodulatory capacities and their contribution to tumor immune evasion. However, the role of aberrant sialylation in colorectal cancer and the consequences of complete tumor desialylation on antitumor immunity remain unstudied. Cornelissen et al. used CRISPR/Cas9 technology to KO CMAS gene in MC38 cell line and found that compared with control MC38 cell line, mouse colorectal cancer MC38 cell line (MC38 Sia^null) with complete knockout of CMAS gene significantly promoted tumor growth in vivo (Fig. 2). The enhancement of tumor growth caused by MC38 Sia^null cell line can be attributed to the decrease of CD8⁺T cell frequency in the tumor microenvironment. MC38 Sia^null cell line can induce CD8⁺T cell apoptosis in an antigen-independent manner, but the frequency of immune cells in tumor-draining lymph nodes was not affected. And in human colorectal cancer cells, low CMAS gene expression is associated with reduced recurrence free survival. In conclusion, these results show that CMAS gene is one of the key genes of sialylation pathway, which provides a new research idea for the treatment of colon cancer^[2].

 

Figure 1  Different effects of CMAS gene knockout MC 38 cell line and control MC38 cell line on tumor growth in vivo

Reveal the relationship between Tn antigen and immunosuppressive tumor microenvironment

Expression of the tumor-associated glycan Tn antigen (αGalNAc-Ser/Thr) has been correlated to poor prognosis and metastasis in multiple cancer types. However, the exact mechanisms exerted by Tn antigen to support tumor growth are still lacking. Therefore, Lenneke et al. explored how Tn antigen affects tumor immune cell formation in a colorectal cancer (CRC) mouse model. They found that C1galt1c gene knockout with CRISPR/Cas9 technology could lead to the increase of Tn antigen level on the cell surface of MC38 cell line (MC38-Tn^high). RNA sequencing and subsequent GO term enrichment analysis of our Tn^high glycovariant not only revealed differences in MAPK signaling and cell migration, but also in antigen processing and presentation as well as in cytotoxic T cell responses. The results show that  MC38-Tn^high tumors displayed increased tumor growth in vivo, which was correlated with an altered tumor immune cell infiltration, characterized by reduced levels of cytotoxic CD8⁺T cells and enhanced accumulation of myeloid-derived suppressor cells. But there is no systemic differences in T cell subsets were observed^[3]. 

hCD47-MC38 HuCELL can be used as a model for the in vivo evaluation of human SIRPα antibodies

CD47 is broadly expressed on all normal cell lines or tissues, SIRPα(Signal regulatory proteinα) is a typical inhibitory immune receptor in SIRP family. After binding with CD47, it can prevent cell lines from being swallowed by macrophages. Daniel Xianfei et al. developed the human CD47 and SIRPα double knock-in mouse model (CD47/SIRPα HuGEMM™) via CRISPR/Cas9 technology. And they have also generated mouse syngeneic MC38 cell line to express human CD47 (hCD47-MC38 HuCELL™). They transplanted hCD47-MC38 HuCELL to CD47/SIRPα HuGEMMHugemm mice, which was used to evaluate the efficacy of anti human CD47 antibody Hu5F9. The experiment results show that hCD47/hSIRPα double knock-in model and hCD47-MC38 HuCELL provide a powerful preclinical platform, which can not only effectively evaluate the action mode and in vivo efficacy of human specific anti-CD47 antibody, but also can be used as a model for in vivo evaluation of human SIRPα antibodies, and a proof of concept for combination therapy with other immune checkpoint inhibitors or immunomodulators^[4].

Ubigene can achieve higher cutting efficiency with developed CRISPR-U™ technology. And Ubigene has successfully modified more than 5000 genes from over 100 cell lines, including the MC38 cell line. Ubigene provides services all over the world. Now Ubigene is offering a time-limited promotional price for gene-editing cell line services, including Knockout/knockin/point mutation/overexpression.  For more details, please feel free to contact us!

References

[1] Zhou, Xiu-Man, et al. "Intrinsic expression of immune checkpoint molecule TIGIT could help tumor growth in vivo by suppressing the function of NK and CD8⁺T-cells." Frontiers in immunology 9 (2018): 2821.

[2] Cornelissen, Lenneke AM, et al. "Disruption of sialic acid metabolism drives tumor growth by augmenting CD8+ T cell apoptosis." International journal of cancer 144.9 (2019): 2290-2302.

[3] Cornelissen, Lenneke AM, et al. "Tn antigen expression contributes to an immune suppressive microenvironment and drives tumor growth in colorectal cancer." Frontiers in oncology 10 (2020): 1622.

[4] He, Daniel Xianfei, et al. "Anti-human CD47 antibody Hu5F9 inhibits MC38 tumor growth in hCD47/hSIRPα double knock-in mice." (2020): 5615-5615.