Table 1.

Antigen targets in colon cancer, their biological role, results of in vivo studies and clinical trials for peptide vaccination.

Peptides	Targets	Mechanism	Type of Study	Results	Side Effects	Comments	Reference
EphA2-derived peptide	EphaA2	EphA2-specific CTL	In vivo: colon cancer liver metastasis mouse model	Prevents progression of tumour in the liver	No liver or kidney toxicity	Safe to apply clinically to treat colon cancer liver metastases	[21]
RNF43-721			Phase 1 clinical trial in colorectal cancer			Vaccinations were well tolerated	[31]
ABT-737	Bcl-2 small molecule inhibitor	Inhibition of anti-apoptotic Bcl-2 family	In vivo: mouse colon cancer model	Sensitized cancer cells to the antitumor effect of antigen-specific immunotherapy		Improve survival rate	[32]
Multi- peptide cocktail:Epitomes of HER2, MVF, GMP and n-MDP	Multiple targets:HER2, MVF, GMP and n-MDP	Inhibition of EGF-2	Phase 1 clinical trial in solid cancers including 4 colorectal	25% SD	No serious adverse events, autoimmune disease, or cardiotoxicity		[33]
Endoglin	Endoglin	Inhibition of angiogenesis	CT26 colon carcinoma mouse model	Inhibition of tumour growth and angiogenesis			[34]
CEA691	Carcinoembryonic antigen	Induction of tumor-specific CTLs	Colon carcinoma mouse model	CEA-specific CTL responses were augmented Antigen-specific proliferation of splenocytes and secretion of Th1 cytokines increased Survival rate increased		Potential for future clinical applications	[35]
MUC1, MHC class II helper peptides	A cell surface associated protein:Mucin 1	Stimulation of IFN-gamma-producing CD4 (+) helper cells,Induction of CTLs specific to MUC1 and other undefined MC38 tumour antigens	A MUC1-tolerant colon cancer mouse model	In the therapeutic setting, tumour burden was significantly reduced In the prophylactic setting, tumour was completely rejected		Potential for future clinical applications	[36]
CEA526–533, NP52–59	Carcinoembryonic antigen	Activation of tumor-specific CTLs	Murine colon adenocarcinoma mouse model
OX40L	TNF family protein		CT26 colon cancer mouse model	Inhibition of tumour growth in a dose and route dependent manner Repression of CRC lung metastasis in a dose dependent manner		Potential use for colon metastasis treatment	[37]
Heat-Shock Protein Gp96	Heat-Shock Protein	Induction of tumour-specific CTLs	Clinical trial in colorectal cancer liver metastases after tumour resection	Induction of colon carcinoma-specific CTLs in 52% patients Two-year overall survival and disease-free survival were significantly improved	No significant toxicity	Possible clinical benefit for CRC liver metastatic patients	[38]
SART3109–118 SART3315–323	SART	Induction of tumour-specific CTLs	Clinical trial in patients with advanced colorectal cancer	Increased cellular immune responses to the tumour and the vaccinated peptide Dose-dependent responses	No serious adverse events	Encourage further development of SART3 peptide vaccine for colorectal cancer patients	[39]
Lck-derived peptides		Induction of tumor-specific CTLs					[40]
CEA605–613 and Flt3L	CEA	Induction of tumor-specific CTLs	Clinical trial metastatic or recurrent colorectal cancer				[41]