Pathobiological behavior and molecular mechanism of signet ring cell carcinoma and mucinous adenocarcinoma of the stomach: a comparative study.
OBJECTIVE
To elucidate the distinctive pathobiological behavior between signet ring cell carcinoma (SRC) and mucinous adenocarcinoma of the stomach.


METHODS
Based on the histological growth patterns and cell-functional differentiation classifications of stomach carcinoma, we conducted a series of comparative studies. All paraffin-embedded and frozen blocks were collected from the files of Cancer Institute of China Medical University. On the basis of histopathological observation, we applied enzymatic and mucous histochemistry, immunohistochemistry, flow cytometry (FCM) and molecular biology to compare these two categories of gastric cancers in terms of the DNA ploidy, proliferative kinetics, the expression of gastric carcinoma associated gene product and instabilities of mitochondrial DNA (mtDNA).


RESULTS
Gastric SRC was commonly seen in females below 45 years, mostly presenting diffuse growth and ovary or uterine cervix metastasis. The majority of SRC were absorptive and mucus-producing functional differentiation type (AMPFDT), which growth relied on estrogen. Meanwhile, stomach mucinous adenocarcinomas were mostly observed in males over 50 years, prone to massive growth or nest growth and extensive peritoneal infiltration, showing two categories of cell-functional differentiation types: AMPFDT and mucus-secreting functional differentiation type (MSFDT). Expressions of ER, enzyme c-PDE and 67kDaLN-R in SRC were evidently higher than that in mucinous adenocarcinoma, while expressions of LN, CN-IV, CD44v6, and PTEN protein were obviously lower in SRC than that in mucinous adenocarcinoma (P<0.05). There was no statistic significance in VEGF, ECD and instabilities of mtDNA (P>0.05) between the above two gastric carcinomas.


CONCLUSIONS
Though SRC and mucinous adenocarcinoma were both characterized by abundant mucus-secretion, they were quite different in morphology, ultrastructure, cell-functional differentiation and protein expression, indicating different mechanisms of carcinogenesis. We concluded that combining histological growth patterns, cell-functional differentiation type with tumor related markers might be significant in early diagnosis and prognosis assessment for SRC and mucinous adenocarcinoma of the stomach.
The Fourth Laboratory, Cancer Institute, The First Affiliated Hospital of China Medical University, Shenyang 110001, Liaoning Province, China.
Xue-Fei
XF
Yang
Lin
L
Yang
Xiao-Yun
XY
Mao
Dong-Ying
DY
Wu
Su-Min
SM
Zhang
Yan
Y
Xin
D002288:Adenocarcinoma, Mucinous / Q000473:pathology* / Q000503:physiopathology; D014408:Biomarkers, Tumor; D018279:Carcinoma, Signet Ring Cell / Q000473:pathology* / Q000503:physiopathology; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D013274:Stomach Neoplasms / Q000473:pathology* / Q000503:physiopathology
D014408:Biomarkers, Tumor