Using reverse transcription in conjunction with the quantitative real-time PCR or digital droplet PCR, the transcriptome profiling of human chromosome 18 has been carried out in liver hepatocytes and hepatoblastoma cells (HepG2 cell line) in terms of the absolute number of each transcript per cell. The transcript abundance varies within the range of 0.006 to 9635 and 0.011 to 4819 copies per cell for HepG2 cell line and hepatocytes, respectively. The expression profiles for genes of chromosome 18 in hepatocytes and HepG2 cells were found to significantly correlate: the Spearman's correlation coefficient was equal to 0.81. The distribution of frequency of transcripts over their abundance was bimodal for HepG2 cells and unimodal for liver hepatocytes. Bioinformatic analysis of the differential gene expression has revealed that genes of chromosome 18, overexpressed in HepG2 cells compared to hepatocytes, are associated with cell division and cell adhesion processes. It is assumed that the enhanced expression of those genes in HepG2 cells is related to the proliferation activity of cultured cells. The differences in transcriptome profiles have to be taken into account when modelling liver hepatocytes with cultured HepG2 cells.
Ispol'zuia obratnuiu transkriptsiiu sovmestno s kolichestvennoĭ PTsR v real'nom vremeni ili tsifrovoĭ kapel'noĭ PTsR, provedeno profilirovanie transkriptoma khromosomy 18 cheloveka v gepatotsitakh pecheni i kletkakh gepatoblastomy (kletochnaia liniia HepG2) v terminakh absoliutnogo chisla kopiĭ kazhdogo transkripta na kletku. Kolichestvennaia predstavlennost' transkriptov var'iruet v predelakh ot 0,006 do 9635 i ot 0,011 do 4819 kopiĭ na kletku dlia kletochnoĭ linii HepG2 i gepatotsitov pecheni, sootvetstvenno. Obnaruzhena znachitel'naia korreliatsiia mezhdu ékspressieĭ genov khromosomy 18 v gepatotsitakh i kletkakh HepG2: koéffitsient korreliatsii Spirmana sostavil 0,81. Raspredelenie chastoty transkriptov po ikh kolichestvennoĭ predstavlennosti iavliaetsia bimodal'nym dlia kletok linii HepG2 i unimodal'nym dlia gepatotsitov pecheni. Bioinformaticheskiĭ analiz differentsial'noĭ ékspressii genov vyiavil, chto geny khromosomy 18, pokazyvaiushchie povyshennuiu ékspressiiu v kletkakh HepG2 po sravneniiu s gepatotsitami, assotsiirovany s protsessami kletochnogo deleniia i kletochnoĭ adgezii. Predpolagaetsia, chto usilennaia ékspressiia étikh genov sviazana s proliferativnoĭ aktivnost'iu kul'tiviruemykh kletok HepG2. Razlichiia transkriptomnykh profileĭ dolzhny uchityvat'sia pri ispol'zovanii kletok linii HepG2 v kachestve modeli gepatotsitov pecheni.
Keywords: HepG2; chromosome 18; hepatocytes; quantitative PCR; transcriptome.