[Regulation and mechanism of Notch signaling pathway in small cell lung cancer].
OBJECTIVE
To investigate the status of Notch signaling pathway in small cell lung cancer (SCLC).


METHODS
Expression plasmids of pEFBOS-NIC-MYC and pEFBOS-neo were transfected into NCI-H446 cells. Stably transfected cell lines were selected and their growth rates were examined by MTT method. Expression of downstream genes along the Notch signaling pathway were studied by RT-PCR. Protein expression of euroendocrine markers of CgA and NSE were detected by Western blot analysis and immunocytochemistry.


RESULTS
The expression of HES1 was increased in the pEFBOS-NIC-MYC group, but the expression of hASH in the pEFBOS-NIC-MYC group was decreased significantly. The transfected cells with pEFBOS-NIC-MYC plasmid showed a significantly slower growth rate compared with that of two control groups (P < 0.05, Student's t-test). Immunocytochemistry of NSE showed that PUs in the NIC transfected group, sham group and negative control group were 7.21 ± 0.59, 28.25 ± 1.46, 30.57 ± 1.31 respectively, the former one was smaller than the values of the latter two significantly (P < 0.01). Western blot analysis showed the grave scales of CgA in NIC transfected group and sham group to be 0.54 ± 0.03 and 0.99 ± 0.05 respectively (grave scales of the negative control was set as 1.00), the former one significantly smaller than that of the other two groups (P < 0.01). The grave scales of NSE in the NIC transfected group and sham group were 0.43 ± 0.02 and 1.07 ± 0.09 respectively (grave scales of the negative control was set as 1.00) and the former one was significantly smaller than the other two groups (P < 0.01).


CONCLUSIONS
Notch signaling pathway regulates SCLC cells through its inhibitory effect on hASH1 transcription via HES1 along with an expression inhibition of neuroendocrine markers in SCLC.
Zhang
Xiu-ming
XM
Department of Pathology, the First Affiliated Hospital, Zhejiang University, Hangzhou, China.
Wang
Jie-xin
JX
Lei
Xiao-guang
XG
Cheng
Hui
H
Wang
Ling-ling
LL
Yao
Gen-you
GY
D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D053379:Chromogranin A / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D010957:Plasmids; D051881:Receptor, Notch1 / Q000378:metabolism* / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D055752:Small Cell Lung Carcinoma / Q000378:metabolism / Q000473:pathology; D000072056:Transcription Factor HES-1; D014162:Transfection
D051792:Basic Helix-Loop-Helix Proteins; D053379:Chromogranin A; D018398:Homeodomain Proteins; D010751:Phosphopyruvate Hydratase; D051881:Receptor, Notch1; D011994:Recombinant Proteins; D000072056:Transcription Factor HES-1; C065500:ASCL1 protein, human; C497761:NOTCH1 protein, human; C078493:HES1 protein, human