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Dave et al. Nibrin expression in OSCC

Table 2: Univariate survival analysis (Kaplan-Meier survival function) of Nibrin expression
Variable n Patients relapsed or died, n (%) Log-rank df P
Relapse free survival
Nibrin (total patients, n = 78)
Weak 38 15 (39)* 0.006 1 0.937
Strong 40 17 (42)*
Nibrin (early stage patients, n = 35)
Weak 12 1 (8)* 3.884 1 0.049
Strong 23 10 (43)*
Nibrin (advanced stage patients, n = 43)
Weak 26 14 (54)* 0.593 1 0.441
Strong 17 7 (41)*
Overall survival
Nibrin (total patients, n = 90)
Weak 42 19 (45)# 0.112 1 0.737
Strong 48 20 (42)#
Nibrin (early stage patients, n = 38)
Weak 13 2 (15)# 0.659 1 0.417
Strong 25 7 (28)#
Nibrin (advanced stage patients, n = 52)
Weak 29 17 (59)# 0.010 1 0.920
Strong 23 13 (56)#
*: patients relapsed; #: patients died

difference in Nibrin expression between OSCC tissues Plisiecka-Halasa et al. also showed that in human
[25]
and their corresponding adjacent normal tissues (t = ovarian tumor tissues Nibrin expression was marked
-0.455, df = 99, P = 0.657). Along with that in OSCC as strong nuclear staining which was present in both
tissues, Nibrin expression was significantly positively tumors and normal tissues. Further, Nibrin expression
correlated with tumor differentiation and significantly is up-regulated in adjacent normal tissues of OSCC
inversely correlated with tumor size and tumor stage, tissue which is compatible with the hypothesis that
[32]
suggesting that up-regulation of Nibrin may be an Nibrin is a tumor suppressor gene. In contrast with
[30]
early event in OSCC development. In accordance our findings, Hsu et al. showed that Nibrin over
expression was significantly correlated with high tumor
with our results, Ali-Fehmi et al. also showed that size and metastatic dieses in OSCC patients which
[31]
NBS1 does not show markedly higher expression in may be because of the inclusion of more number of
all ovarian cancer patients compared to women with patients with locally advanced diseases. Ehlers et al.
[33]
serous cyst adenoma and those with normal ovaries. also showed that Nibrin was associated with strong
tumor severity and metastatic death marker in uveal
melanoma. However, similar expression of NBS1
in class 1 tumors and normal uveal melanocytes
suggests that up-regulation of NBS1 may be a late
event in melanoma progression.

Kaplan-Meier univariate survival analysis showed
that in patients with early stage disease high number
of patients relapsed with strong Nibrin expression.
However, our findings not only observed increased
expression pattern of Nibrin in early stage patients
but also found a strong correlation between increased
Nibrin expressions in the onset of the disease with
higher probability of recurrence. This could be
attributed to the fact that since Nibrin acts as a sensor
molecule of MRN complex which further activates the
other DNA repair molecules, it might have a plausible
Figure 2: Kaplan-Meier univariate survival analysis of patients with role in constitutively activating these downstream
early stage disease indicating significant high incidence of disease
relapse in patients with strong Nibrin expression (P = 0.049). RFS: molecules eventually leading to disease relapse
[30]
relapse-free survival in patients. While Hsu et al. found that in OSCC
440 Journal of Cancer Metastasis and Treatment ¦ Volume 2 ¦ November 25, 2016