NOTES
3
Discussion
GRC-1, we used the corresponding antisense oligonucleo-
tide to block the expression of GYLZ-RCC18. After the
transfection, the growth and proliferation activity of
GRC-1 cells were inhibited significantly. At the same time,
blocking the expression could also increase the mortality
and apoptosis ratio of renal cell carcinoma, and the curve
of mortality and apoptosis were not similar, so we de-
duced that GYLZ-RCC18 may produce an important pro-
tective effect on renal cell carcinoma by antidead and an-
tiapoptosis mechanisms respectively. So the expression of
GYLZ-RCC18 may be closely related to the deathproof
speciality of renal cell carcinoma. It also implied that the
expression of GYLZ-RCC18 may account for multidrug
resistance and irregular recurrence of renal cell carcinoma.
GYLZ-RCC18 provided a new idea for the research of
those special biobehaviors; third, by using antisense oli-
gonucleotide we found vast GRC-1 cells were killed spe-
cially but the HK-2 suffered little trauma, which indicated
that targeting GYLZ-RCC18 to perform gene therapy may
be a potential effective method for renal cell carcinoma.
In conclusion, the study showed that GYLZ-RCC18
is a novel gene closely related to renal cell carcinoma. The
expression of it could promote the growth and prolifera-
tion activity of renal cell carcinoma. It can also produce
anti-dead and anti-apoptosis effect on renal cell carcinoma.
The overexpression of GYLZ-RCC18 plays a crucial role
in generation and development of renal cell carcinoma.
Research of it could provide not only a new clue for the
study of the mechanism of the occurrence but also the
academic instruct of diagnosis and gene therapy of renal
cell carcioma.
Renal cell carcinoma is one of the commonest can-
cers in urology. The incidence of renal cell carcinoma is
about 3% of all the human cancers, and increases by about
2% annually[4]. Its biological beheavior is very vagarious
and the mechanism of its generation and development still
remains unknown. In recent years, significant progress in
genetics has indicated that the loss of VHL kidney cancer
gene and FHIT gene results in the development of 50%
clear cell kidney cancers[5]. The mutation of WT178 and
high expression of protooncogene c-myc, EGFR52,
c-met57, c-Ha-ras, c-fos, c-fms, f-faf-1mRNA and low
expression HER-2 (erb B-2) mRNA are associated with
the generation and development of RCC[6,7]. But all of
these genes are not RCC-specially expressed genes and
have little value of diagnosis and therapy in renal cell car-
cinoma.
Based on the clone of the renal cell carcinoma re-
lated novel gene GYLZ-RCC18 fragment[1], we used the
SMART RACE technique to clone the full length of
GYLZ-RCC18. The sequence analysis indicated that the
full length of GYLZ-RCC18 is about 3.5 kb long and lo-
cated at No. 14 chromosome. It contains 3 independent
reading frames. The cDNA is relatively long and has sev-
eral overlapping reading frames at the same time, which
implies that GYLZ-RCC18 may be an important gene with
complex function although the function of the protein is
unknown. Deeper research of this novel gene could ex-
ploit a new method for researching the renal cell carci-
noma.
To study the actual function of GYLZ-RCC18, first,
we designed the primer in its first reading frame which
could amplify 504 bp long fragment of GYLZ-RCC18.
The results showed that the expression quantum is about
20% of house-keeping gene E-actin. It implied that GYLZ-
RCC18 is a mid-abundance expression gene. The expres-
sion quantum of GYLZ-RCC18 in renal cell carcinoma
tissue or cell line is about 1k9-fold higher than in normal
kidney tissues or cell lines, which was confirmed by
Northern blot analysis before[1]. A noticeable result was
that GYLZ-RCC18 was specially expressed in renal cell
carcinoma at a high level. The results verified that GYLZ-
RCC18 is a gene exclusively and highly expressed by re-
nal cell carcinoma. On the other hand, we found that
GYLZ-RCC18 overexpressed in higher grades and stages
of renal cell carinoma. It indicated that GYLZ-RCC18 may
be a novel oncogene, and its continuous expression may
play a key role in the evolution of kidney tissue from
normal kidney to cancer and in the development of renal
cell carcinoma. So we considered that GYLZ-RCC18
could be a new special marker for renal cell carcinoma,
especially in evaluation of higher grade or stage samples;
second, to ulteriorly estimate the role of GYLZ-RCC18 in
Acknowledgements This work was supported by the National Natural
Science Foundation of China (Grant No. 39870841).
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(Received May 15, 2001)
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Chinese Science Bulletin Vol. 46 No. 19 October 2001