MGc80-3和HeLa的短串联重复（STR）基因型有部分重叠，引发了对MGc80-3细胞系受到了污染的怀疑。然而，以往的研究并未证明MGc80-3是否被HeLa细胞完全替代，只是与HeLa细胞混合存在（共存），或者是与HeLa细胞发生体细胞杂交。除了STR基因型分析外，我们采用了多种方法，包括单核苷酸多态性基因分型、聚合酶链反应、人乳头瘤病毒18型（HPV-18）片段筛查、染色体核型分析、异种移植物的病理检查、组织特异性90个基因的表达标志和高通量RNA测序来确定MGc80-3的性质。我们的研究发现，与HeLa细胞的STR基因型部分重叠（64.62%至71.64%）不能将MGc80-3确定为HeLa细胞系。然而，在D13S317位点上，我们检测到MGc80-3中存在独特于HeLa细胞的STR 13.3重复等位基因。几乎所有的MGc80-3细胞的基因组中都存在HPV-18片段，以及像M7和M12这样的特定HeLa细胞标记染色体。基于90个基因表达标志物的分子分析仍然将MGc80-3认定为胃癌细胞，使用了算法分析。MGc80-3中多个基因的表达模式与HeLa细胞相比有很大差异，表明某些特征属于胃癌细胞系。高通量RNA测序显示MGc80-3中基因表达呈现出明显的模式。综上所述，MGc80-3细胞系是与HeLa细胞发生体细胞杂交的胃癌细胞系，而非纯正的胃癌细胞系。© 2023 UICC.

The short-tandem-repeats (STR) profiles of MGc80-3 and HeLa partially overlap, raising suspicion of contamination in the MGc80-3 cell line. However, there has not been any relevant study demonstrating whether MGc80-3 was fully replaced by HeLa cells, just mixed with HeLa cells (co-existing), or was a somatic hybrid with HeLa cells. In addition to STR profiling, various approaches, including single nucleotide polymorphisms genotyping, polymerase chain reaction, screening for human papillomaviruses type 18 (HPV-18) fragment, chromosome karyotyping, pathological examination of xenografts, tissue-specific-90-gene expression signature and high-throughput RNA sequencing were used to determine the nature of MGc80-3. Our study found that the abnormal STR profile, partially overlapping with that of HeLa cells (64.62% to 71.64%), could not verify MGc80-3 as a HeLa cell line. However, the STR 13.3 repeat allele in the D13S317 locus that seemed to be unique to HeLa cells was detected in MGc80-3. Almost all the MGc80-3 cells exhibited HPV-18 fragments in the genome as well as certain HeLa marker chromosomes, such as M7 and M12. The molecular assay of the 90-gene expression signature still considered MGc80-3 as a stomach cancer using an algorithmic analysis. The expression pattern of multiple genes in MGc80-3 was quite different from that in HeLa cells, which showed that certain characteristics belonged to gastric cancer cell lines. High throughput RNA sequencing showed the distinct patterns of gene expression in MGc80-3. In conclusion, MGc80-3 cell line is a somatic hybrid with HeLa cells rather than a pure gastric cancer cell line.© 2023 UICC.