ABSTRACT
DoBloodGroupsHaveaBiologicalRole207
betweenitandbloodgroupsubstanceA.Rabbitantiseraagainsttumorglycolipidagglutinated typeAredcellsmorereadilythangroupB,AB,or0redcells.Thisandotherexperiments suggestedthattumorglycolipidwasaconstituentofthesurfaceoftumorcells,andthatblood groupAsubstanceandgroupAredcellsmaycontainalargerconcentrationofahaptenstructure similarto,oridenticalwith,thecarbohydratemoietyofthetumorglycolipidthandosubstances orredcellsofgroupBorO(H)(45).Hakomorietal.(45)suggestedthatitmaybemore difficultfortheimmunologicalsystemofthegroupApatienttorecognizetumorcells,possessing "A-like"glycolipid,asforeignbecauseofthelatter'ssimilaritytothehost'sownAsubstance andthusfailtorejectthem.ThismaypossiblyrelatetotheincreaseofgroupAcomparedwith 0incancerpatients.Otheradenocarcinomaswerefoundtohaveincreasedquantitiesofa cerarnidepentasaccharidewithLeastructureandaceramidehexasaccharidehavingLebactivity (47,54).Increasedlevelsof2~3sialylLeaanddesialylLea,bothinthemalignantcellsand intheplasma,havebeenreportedincolonic,pancreatic,andothercancers(51).
