Inhibitors of glucose transport and glycolysis as novel anticancer therapeutics

Table 2 Expression of glucose transporters and their major characteristics

Protein	Class	Expression	Affinity to glucose	Major features	Expression in cancer
GLUT1	I	Ubiquitous (abundant in brain and erythrocytes)[207]	High[201,208,211]	Constitutive basal glucose uptake[207]	Over-expressed[176,203]
GLUT2	I	Liver, retina, pancreatic islet cells[176,198]	Low[201,211]	Glucose sensing, fructose transport[176,200]	Abnormal[176,202-204]
GLUT3	I	Brain[196]	High[201,211]	Supplements GLUT1 in brain[176,196]	Over-expressed[176,205]
GLUT4	I	Muscle, fat, heart[210]	High[208,209,211]	Insulin responsive[210]	Abnormal[188]
GLUT5	II	Intestine, testis, kidney, erythrocytes[213,214]	Very low[212]	Fructose transport[212]	Abnormal[176,203]
GLUT6	III	Spleen, leukocytes, brain[215]	Low[215]	Sub-cellular redistribution[216]	UD[203]
GLUT7	II	Liver, intestine, colon, testis, prostate[216,217]	High[217]	Glucose and fructose transport[217]	ND
GLUT8	III	Testis, brain[219]	High[219]	Sub-cellular redistribution, multisubstrates[216]	Over-expressed[218]
GLUT9	II	Liver, kidney, pancreatic cells[220,222]	High[221]	Multisubstrates[216]	UD[203]
GLUT10	III	Liver, pancreas[223]	High[224]	Glucose transport[224]	ND
GLUT11	II	Heart, muscle[225]	Low[225]	Inhibited by fructose[225]	ND
GLUT12	III	Heart, prostate, muscle, fat, intestine[226]	High[227]	Insulin-reponsive[226]	Abnormal[206]
HMIT	III	Brain[228]	No	H+/myo-inositol transport[228]	ND
GLUT14	I	Testis[229]	ND	ND	ND

GLUTs: Glucose transporters; HMIT: H⁺/myo-inositol transporter; ND: Not determined; UD: Undetectable.