乳腺浸润性微乳头状癌中CD44^+/CD24^(-/low)和CD24^+表型细胞的研究

Study on CD44^+/CD24^(-/low) and CD24^+ tumor cells in invasive micropapillary carcinoma of the breast

目的研究乳腺浸润性微乳头状癌(invasive micropapillary carcinoma,I MPC)的干细胞表型,从干细胞和上皮间质转化(epithelial-mesenchymal transition,EMT)角度探讨I MPC高侵袭、高转移恶性生物学行为的原因。方法选取术前未经放化疗治疗患者的I MPC82例和乳腺非特殊型浸润性导管癌(invasive ductal carcinoma nototherwise specified,IDC-NOS)80例石蜡包埋组织标本切片,通过免疫组织化学双染技术检测两组肿瘤组织中CD44+/CD24-/low(CD24-)和CD24+的表达、定位和分布情况,并分析其与各临床病理学特征之间的关系。定量资料采用Student'st检验,定性资料采用Mann-Whitney U检验、Kruskal-Wallis检验、χ2检验或校正χ2检验。两组之间相关性采用Spearman's秩相关分析。结果(1)I MPC组肿瘤细胞的CD44+/CD24-/low阳性表达率(48.8%,40/82例),明显高于IDC-NOS组(31.3%,25/80例)(χ2=5.180,P=0.023)。(2)53.7%(44/82例)的I MPC微细间质组织内见单个散在的CD44+/CD24-/low肿瘤细胞,且该细胞免疫组织化学染色Vi mentin及α-SMA阳性,E-Cadherin阴性。IDC-NOS间质内罕见CD44+/CD24-/low肿瘤细胞。(3)I MPC微乳头结构中CD44+/CD24-/low与间质内的CD44+/CD24-/low阳性表达细胞呈明显正相关(r=0.516,P<0.001),并且I MPC微乳头结构及间质中CD44+/CD24-/low阳性表达在有无淋巴管侵犯和有无淋巴结外软组织浸润方面的差异均有统计学意义(P<0.050),即有淋巴管侵犯及淋巴结外软组织浸润者CD44+/CD24-/low阳性表达率较高。(4)I MPC组中CD24+细胞阳性表达率79.3%(65/82例),明显高于IDC-NOS组(60.0%,48/80例)(χ2=7.126,P=0.008),且I MPC中淋巴结转移阳性组CD24的表达高于阴性组,差异有统计学意义(χ2=8.834,P=0.003)。结论I MPC肿瘤细胞中干细胞的存在及上皮间质转化可能是I MPC高淋巴管侵犯、高淋巴结转移及耐药等恶性生物学行为的重要原因。研发针对乳腺癌干细胞的药物也可作为治疗乳腺癌的一个方法。

Objective To study the stem cell phenotype of invasive micropapillary carcinoma （IMPC） of the breast. Through the stem cell and epithelial-mesenchymal transition, the causes of biological behaviour of high metastasis and invasion of IMPC was investigated. Methods The expression, location and distribution of CD44 and CD24 were determined by immunohistochemical double staining in 82 cases of IMPC and 80 cases of invasive ductal carcinoma not otherwise specified （IDC-NOS）, undergoing without preoperative chemotherapy and radiotherapy, and their relationship with clinicopathological features was analyzed. Student＇s t test was used for quantitative data. Mann-Whitney U test, Kruskal-Wallis test and x^2 test or revised x^2 test were used for qualitative data. Spearman＇s test was used for association between groups. Results The positive expression rate of CD44^＋/CD24^-/low tumor cells was higher in the IMPC group（48.8% ,40/82 cases） than in the IDC-NOS group （31.3%, 25/80 cases）（x^2 =5. 180,P=0. 023）. The CD44^＋/CD24^-/low tumor cells was also detected in adjacent stroma surrounding the mieropapillary structure in 53.7% （44/82 cases） of IMPC, with Vimentin and α- SMA positive and E-Cadherin negative, but scarce in stroma of IDC-NOS. （3） The CD44^＋/CD24^-/low tumor cells in micropapillary structure of IMPC was positively associated with that in stroma （r=0. 516, P〈0. 001）, moreover, they were both associated with lymphovascular invasion and extranodal extension respectively, and there was statistical difference between lymphovascular invasion and extranodal extension （P〈 0. 050）, that is the positive expression rate of CD44^＋/CD24^- /low in lymphovascular invasion and extranodal extension was high. （4） The positive expression rate of CD24^＋ tumor cells was also higher in IMPC （65/82 cases） than in IDC-NOS （48/80 cases） （x^2 =7. 126, P= 0. 008）, and in IMPC the expression of CD24^＋ was higher in positive lymph node metastasis than in negative, with statistical difference （x^2=8. 834, P= 0. 003）. Conclusions The existence of stem ceils and epithelialmesenchymal transition in IMPC tumor cells may play an important role in aggressiveness and higher metastatic risk of IMPC of the breast. It can be a method to develop drugs targeting breast cancer stem cells.