| Abstract: | 研究目的：妊娠相關乳腺癌是發生在懷孕期間或分娩一年內。是最具侵犯性臨床病程和死亡率最高的乳腺惡性腫瘤。但是，無論是分子或細胞機制，或那些特定分子鏈接到攻擊和侵襲的妊娠相關乳腺癌，都未能確定。肌上皮是唯一的腫瘤抑制因子的來源，包括Maspin，腎母細胞瘤1（WT-1），p63和p73，有顯著抑制腫瘤細胞旁分泌生長和侵襲。 妊娠相關乳腺癌顯著降低肌上皮p63的表達，而在相關上皮則有強烈的胞質p63表達。我們目前的研究試圖進一步闡明具細胞質p63表達的這些正常或增生上皮 其細胞和分子表現，以評估：（1）是否具有腫瘤抑制基因或其他惡性腫瘤相關變化之異常表達，以及（2）與形態相似的無細胞質p63表達者進行比較，他們的DNA拷貝數是否有很大的差別。
研究方法及資料：我們的研究使用福爾馬林固定，石蠟包埋組織塊包括20例妊娠相關乳腺癌與級別和年齡匹配的20例非妊娠相關乳腺癌。我們的研究採用免疫組織化學方法與侵略性和侵襲相關的標記來評估這些上皮細胞。應用兩種技術方法進行研究。首先，設置6個連續切片進行免疫染色，標記是已知的腫瘤抑制基因，包括maspin，WT-1，p63，p53和p73基因和增殖標記 Ki-67。這些標誌物的表達在肌上皮細胞及與肌上皮細胞相關之腺泡，在不同的切面都以數位照相和在一個標準的電腦高放大倍率下判讀。其次，檢查這些腺泡之物理性，以確定它們是否具有完全或優先相關或相似的形態或相同免疫組織化學呈現。評估DNA拷貝數是否有很大的差別，其形態類似相對比無胞質p63的表達，和正常或增生小葉細胞質均勻腺泡細胞有p63的表達，從4例 妊娠相關乳腺癌和形態比較小葉（同一病理類型，分級與類似的結構和大小）無細胞質p63表達之4個非妊娠相關乳腺癌例進行顯微切割。顯微切割之細胞進行到DNA提取和陣列比較基因組雜交（陣列 CGH）技術。
研究結果：與形態類似的對應的非妊娠相關乳腺癌相比，這些正常或增生的小葉具有細胞質 p63表達顯示了以下獨特的特色：（1）同時減少或失去多腫瘤抑制基因的表達，（2）與浸潤癌細胞有相似的形態和免疫組織化學呈現，（3）所有四例妊娠相關乳腺癌在45個染色體上，顯著得到或失去DNA拷貝數之位點，（4）與形態、血管生成、粘附和細胞內的運輸有關的基因改變。
結論：在正常或增生的上皮細胞內異常亞細胞局部定位的p63表達，可能出現顯著的侵襲和有助於提高這些細胞的侵略性。
(WT-1), p63, and p73, which show significant paracrine inhibition on tumor cell growth and invasion in vitro. PABC had significantly reduced nuclear p63 expression in myoepithelia, while intense cytoplasmic p63 expression in associated epithelia. Our current study attempted to further elucidate the cellular and molecular profiles of these normal or hyperplastic appearing epithelia with cytoplasmic p63 expression. Our aims are to assess: (1) whether they harbor aberrant expression of other tumor suppressors or malignancy-associated changes, and (2) whether they differ substantially in DNA copy numbers compared to morphological similar counterparts without cytoplasmic p63 expression.
Methods and Materials: Formalin-fixed, paraffin-embedded tissue blocks from 20 cases of PABC and 20 cases of stage, grade, and age matched non-PABC were used for our study. Our study assessed these epithelia using immunohistochemistry with a panel of aggressiveness and invasiveness related markers. Two technical approaches were used. First, sets of six consecutive sections were immuno-stained for known tumor suppressors, including maspin, WT-1, p63, p53, p73, and proliferation marker Ki-67. The expression of these markers in myoepithelial and associated epithelial cells of the same acini at different sections were digitally photographed and reviewed under high magnification in a standard computer. Second, the physical distribution of these acini was examined to determine whether they were exclusively or preferentially associated or shared a similar morphological or immunohistochemical profile, with invasive lesions. To assess whether they differ substantially in DNA copy numbers compared to their morphologically similar counterparts without cytoplasmic p63 expression, normal or hyperplastic lobules with uniform cytoplasmic p63 expression in acinar cells from 4 PABC cases and morphologically comparable lobules (the same histological type, grade, and similar architecture and size) without cytoplasmic p63 expression from 4 non-PABC cases were microdissected. Microdissected cells were subjected to DNA extraction and array-comparative genomic hybridization (array-CGH).
Results: Compared to their morphologically similar counterparts in non-PABC, these normal or hyperplastic lobules with cytoplasmic p63 expression showed the following unique alterations: (1) Simultaneous reduction or loss of expression of multiple tumor suppressors, (2) Morphological and immunohistochemical resemblance to invasive cancer cells, (3) Significant gain or loss of DNA copy numbers in 45 chromosomal loci in all 4 PABC cases, (4) Alterations in morphogenesis, angiogenesis, adhesion, and intra-cellular trafficking related genes.
Conclusion: Aberrant sub-cellular localization of p63 expression in normal or hyperplastic appearing epithelial cells may significantly contribute to increased invasiveness and aggressiveness of these cells |
