Transcriptional targeting modalities in breast cancer gene therapy using adenovirus vectors controlled by alpha-lactalbumin promoter.
The breast-specific antigen alpha-lactalbumin is expressed in >60% of breast cancer tissues. To evaluate the effect of gene therapy for breast cancer by controlling adenovirus replication with human alpha-lactalbumin promoter, we investigated the activity of a 762-bp human alpha-lactalbumin promoter. Alpha-lactalbumin promoter showed significantly higher activity in MDA-MB-435S and T47D breast cancer cells than in normal breast cell lines or other tumor cell lines. We then developed two novel breast cancer-restricted replicative adenoviruses, AdALAE1a and AdE1aALAE1b. In AdALAE1a, expression of adenoviral E1a gene is under the control of alpha-lactalbumin promoter, and in AdE1aALAE1b, expression of both E1a and E1b genes is under the control of a single alpha-lactalbumin promoter. Both breast cancer-restricted replicative adenoviruses showed viral replication efficiency and tumor cell-killing capability similar to wild-type adenovirus in MDA-MB-435S and T47D cells. The replication efficiency and tumor cell-killing capability of both viruses were attenuated significantly in cells that did not support alpha-lactalbumin promoter. AdE1aALAE1b showed better breast cancer-restricted replication than AdALAE1a, suggesting that a transcriptional targeting modality with alpha-lactalbumin promoter controlling both E1a and E1b gene expression is superior to alpha-lactalbumin promoter controlling only E1a gene expression. Importantly, we found that AdE1aALAE1b could be used to target hormone-independent breast tumors in vivo by inhibiting the growth of MDA-MB-435S s.c. tumors. These data showed that alpha-lactalbumin promoter could regulate the replication of adenovirus to target hormone-independent breast cancers, suggesting that alpha-lactalbumin promoter can be used to develop a novel therapeutic modality for hormone-independent breast cancer.
Li
Xiong
X
Department of Urology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Zhang
Jie
J
Gao
Huanling
H
Vieth
Edyta
E
Bae
Kyung-Hee
KH
Zhang
Yan-Ping
YP
Lee
Sang-Jin
SJ
Raikwar
Sudhanshu
S
Gardner
Thomas A
TA
Hutchins
Gary D
GD
VanderPutten
Dale
D
Kao
Chinghai
C
Jeng
Meei-Huey
MH
D000256:Adenoviridae / Q000235:genetics* / Q000472:pathogenicity; D017500:Adenovirus E1A Proteins / Q000235:genetics; D017501:Adenovirus E1B Proteins / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000235:genetics; D001483:Base Sequence; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000628:therapy*; D045744:Cell Line, Tumor; D017931:DNA Primers; D005260:Female; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D007768:Lactalbumin / Q000235:genetics*; D008297:Male; D042361:Mammary Glands, Human / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D011401:Promoter Regions, Genetic; D011471:Prostatic Neoplasms / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014774:Virulence; D014779:Virus Replication
D017500:Adenovirus E1A Proteins; D017501:Adenovirus E1B Proteins; D017931:DNA Primers; D007768:Lactalbumin