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. 2016 Sep-Dec;20(3):453-461.
doi: 10.4103/0973-029X.190948.

Human MutL homolog 1 immunoexpression in oral leukoplakia and oral squamous cell carcinoma: A prospective study in Indian population

Narendra T Chaudhari  1 , Jagdish V Tupkari  1 , Tabita Joy  1 , Manisha S Ahire  1
Affiliations

Human MutL homolog 1 immunoexpression in oral leukoplakia and oral squamous cell carcinoma: A prospective study in Indian population

Narendra T Chaudhari et al. J Oral Maxillofac Pathol. 2016 Sep-Dec.

Abstract

Background: Mammalian mismatch repair system is responsible for maintaining genomic stability during repeated duplications, and human MutL homolog 1 (hMLH1) protein constitutes an important part of it. Various isolated studies have reported the altered expression of hMLH1 in oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC). Research is lacking in the quantitative estimation and comparison of hMLH1 expression in OL and OSCC.

Aims: To evaluate, quantify and compare hMLH1 immunoexpression in normal oral mucosa, OL and OSCC.

Settings and design: Thirty patients of OL and thirty patients of OSCC formed the study group and thirty patients were included in the control group (normal oral mucosa). Formalin-fixed paraffin wax blocks were prepared from the tissue samples.

Materials and methods: Immunohistochemistry for hMLH1 was performed, and the total number of positive cells was counted in high-power fields, and based on that percentage positivity of hMLH1 was calculated in all the cases.

Statistical analysis: Kruskal-Wallis and t-test were used. P < 0.05 was considered to be statistically significant.

Results: The mean hMLH1 value in control group, leukoplakia and OSCC was 78.26, 54.33 and 40.97 respectively. hMLH1 immunoexpression showed decreasing indexes from control group to leukoplakia and then further to OSCC. hMLH1 expression was significantly lower in OSCC as compared to leukoplakia. There was no significant correlation of mean hMLH1 expression between different clinical and histopathological stages of leukoplakia and OSCC.

Conclusions: hMLH1 immunoexpression was inversely related to the degree of dysplasia. These findings suggest that there is a progressive decrease in hMLH1 expression from control to leukoplakia and further to OSCC. Thus, it can be concluded that hMLH1 can be used as a reliable biomarker for malignant transformation.

Keywords: Mismatch repair system; oral leukoplakia; oral squamous cell carcinoma.

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Figures

Figure 1
Figure 1
(a) Photomicrograph showing parakeratinized stratified squamous epithelium (control) (H&E stain, ×100). (b) Positive human MutL homolog 1 expression predominantly in basal and suprabasal layer of normal mucosa (control) (IHC stain, ×100)
Figure 2
Figure 2
(a) Oral Leukoplakia; Photomicrograph showing mild dysplasia (H&E stain, ×100). (b) Oral Leukoplakia; Photomicrograph showing mild dysplasia (H&E stain, ×400). (c) Oral Leukoplakia; positive human MutL homolog 1 staining in mild dysplasia (IHC stain, ×100). (d) Oral Leukoplakia; positive human MutL homolog 1 staining in mild dysplasia (IHC stain, ×400)
Figure 3
Figure 3
(a) Oral Leukoplakia; Photomicrograph showing moderate dysplasia (H&E stain, ×100). (b) Oral Leukoplakia; positive human MutL homolog 1 staining in moderate dysplasia (IHC stain, ×100)
Figure 4
Figure 4
(a) Photomicrograph of oral squamous cell carcinoma Grade I (H&E stain, ×100). (b) Photomicrograph of oral squamous cell carcinoma Grade I (H&E stain, ×400). (c) Positive human MutL homolog 1 staining in oral squamous cell carcinoma Grade I (IHC stain, ×100). (d) Positive human MutL homolog 1 staining in oral squamous cell carcinoma Grade I (IHC stain, ×400)
Figure 5
Figure 5
(a) Photomicrograph of oral squamous cell carcinoma Grade II (H&E stain, ×100). (b) Faint human MutL homolog 1 staining in oral squamous cell carcinoma Grade II (IHC stain, ×100). (c) Photomicrograph of oral squamous cell carcinoma Grade III (H&E stain, ×100). (d) Faint human MutL homolog 1 staining in oral squamous cell carcinoma Grade III (IHC stain, ×100)
Figure 6
Figure 6
(a) Photomicrograph of oral leukoplakia (H&E stain, ×100). (b) Negative human MutL homolog 1 staining in oral leukoplakia (IHC stain, ×100). (c) Photomicrograph of oral squamous cell carcinoma (H&E stain, ×100). (d) Negative human MutL homolog 1 staining in oral squamous cell carcinoma (IHC stain, ×100)
See this image and copyright information in PMC

References

    1. Liu W, Wang YF, Zhou HW, Shi P, Zhou ZT, Tang GY. Malignant transformation of oral leukoplakia: A retrospective cohort study of 218 Chinese patients. BMC Cancer. 2010;10:685. - PMC - PubMed
    1. Brinkmann O, Kastratovic DA, Dimitrijevic MV, Konstantinovic VS, Jelovac DB, Antic J, et al. Oral squamous cell carcinoma detection by salivary biomarkers in a Serbian population. Oral Oncol. 2011;47:51–5. - PMC - PubMed
    1. de Camargo Cancela M, Voti L, Guerra-Yi M, Chapuis F, Mazuir M, Curado MP. Oral cavity cancer in developed and in developing countries: Population-based incidence. Head Neck. 2010;32:357–67. - PubMed
    1. Warnakulasuriya S, Johnson NW, van der Waal I. Nomenclature and classification of potentially malignant disorders of the oral mucosa. J Oral Pathol Med. 2007;36:575–80. - PubMed
    1. van der Waal I. Potentially malignant disorders of the oral and oropharyngeal mucosa; present concepts of management. Oral Oncol. 2010;46:423–5. - PubMed