中文摘要：

HER2在20%-30%的乳腺癌细胞中过表达,是药物如赫赛汀（Herceptin）的治疗靶点。然而许多病人会产生治疗抵抗,其中一个重要机制是HER2变异体的表达,不同的HER2变异体在生物学上可能会扮演相反的角色。如Δ16HER-2（外显子16缺失）和p95HER2（HER2的羧基端片段）会促进肿瘤细胞转化并且与药物抵抗相关。而Herstatin（内含子8保留）与p100（内含子15残留）能够抑制肿瘤细胞的生长增殖。本文综述了目前主要的HER2变异体在乳腺癌细胞中的表达与共存在疾病进程和赫赛汀抵抗中的临床意义。

英文摘要：

HER2 overexpressed in 20%-30% of breast cancers is a target for anticancer molecular therapies like Herceptin.Howerver,many patients acquire resistance to Herceptin.One important mechanism for this resistance is invovled in the variants of HER2,which have contrasting roles in tumor cell biology.For example,the variants Δ16HER-2（ results from exon 16 skipping） and p95HER2（ carboxy-terminal fragments of HER2） are associated with Herceptin resistance and increased transformation of cancer cells.Herstatin（ results from intron 8 retention） and p100（results from intron 15 retention） can inhibit tumor cell proliferation.This review discusses clinical significance of expression and coexpression of the important HER2 variants in cancer cells in relation to breast cancer progression and Herceptin resistance.