Alternative splicing of NUMB, APP and VEGFA as the features of pancreatic ductal carcinoma.
BACKGROUND
Pancreatic ductal adenocarcinoma (PDAC) is the most common form of malignancy in pancreatic carcinoma. Here we report our discovery on the correlations between transcriptional alternative splicing (AS) of NUMB, APP, VEGFA and PDAC in patients.


METHODS
The expression of NUMB, APP, VEGFA from patient samples was determined by qRT-PCR. AS of these genes was examined through laser induced fluorescence capillary electrophoresis. Correlation between the AS of the genes and results from clinical laboratory examinations were analyzed. Expression of NOTHC1 and NOTCH4 as downstream target genes was examined by qRT-PCR and Western blot.


RESULTS
Quantitative results indicated that expression of NUMB was significantly lower in tumor tissues (TT) than in para-tumor tissues (TP) (P<0.05), while APP (P<0.01) and VEGFA (P<0.05) were significantly higher. AS transcript percentage of NUMB PRR(S) was lower in TT than TP (P<0.05). AS transcript percentage of VEGFA (105+185) was significantly lower in TT than TP (P<0.05) compared to higher expression of VEGFA (206+338) (P<0.05). Regression analysis indicated that AS transcript of NUMB PRR(L) correlated with tumor size (P<0.01), while AS transcripts of APP and VEGFA correlated with results of laboratory examinations. To reveal the correlation between AS and its downstream targets, NOTCH1 and NOTCH4 were selected as NUMB gene targets and detected to be significantly higher in TT than TP (P<0.05).


CONCLUSIONS
Alternative splicing of APP, VEGFA and NUMB may play an important role in pathogenesis of pancreatic ductal adenocarcinoma. Among the 3 genes, PRR(L) form of NUMB gene is highly expressed in TT and positively correlated with tumor size, while PRR(S) is lacking in TT and negatively correlated with NOTCH expression suggesting that PRR(S) might be protective in tumorogenesis and shows NOTCH pathway down regulation ability.
Department of Pancreatic Surgery, Changhai Hospital, Second Military Medical University Shanghai 200433, China.
Kai-Lian
KL
Zheng
Department of Pancreatic Surgery, Changhai Hospital, Second Military Medical University Shanghai 200433, China.
Tian-Lin
TL
He
Department of Pancreatic Surgery, Changhai Hospital, Second Military Medical University Shanghai 200433, China.
Wei-Ping
WP
Ji
R & D Department of Cinoasia Institute Shanghai 200437, China.
Hui
H
Jiang
Department of General Surgery, Ao Young Hospital Suzhou 215617, China.
Ye
Y
Shen
Department of Pancreatic Surgery, Changhai Hospital, Second Military Medical University Shanghai 200433, China.
Gang
G
Li
R & D Department of Cinoasia Institute Shanghai 200437, China.
Si-Bo
SB
Zhu
R & D Department of Cinoasia Institute Shanghai 200437, China.
Bing-Lei
BL
Tong
Department of Pancreatic Surgery, Changhai Hospital, Second Military Medical University Shanghai 200433, China.
Yi-Jie
YJ
Zhang
D017398:Alternative Splicing; D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics*; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010190:Pancreatic Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000473:pathology; D011518:Proto-Oncogene Proteins / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D051881:Receptor, Notch1 / Q000032:analysis / Q000235:genetics; D000074562:Receptor, Notch4; D051880:Receptors, Notch / Q000032:analysis / Q000235:genetics; D047368:Tumor Burden; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
C545487:APP protein, human; D016564:Amyloid beta-Protein Precursor; D014408:Biomarkers, Tumor; D008565:Membrane Proteins; C497761:NOTCH1 protein, human; C106075:NOTCH4 protein, human; D009419:Nerve Tissue Proteins; C113026:NUMB protein, human; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D051881:Receptor, Notch1; D000074562:Receptor, Notch4; D051880:Receptors, Notch; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A
Alternative splicing; NUMB; pancreatic ductal carcinoma