Role of apoptosis proteins survivin, bax and BCL-XL in laryngeal squamous cell carcinoma progression

الملخص EN

Aims: we used immunohistochemistry to investigate a potential role of SVV as an early predictor of malignant transformation in precancerous and cancerous lesions of the larynx, we also sought to examine the expression of Bcl-XL and Bax in laryngeal SCC, analyze the relationships between their expression and prognostic factors including site, histological grade, clinical staging and lymph node metastasis. Methods & Results: This study included 6 normal laryngeal mucosae, 7 dysplastic laryngeal epithelia, 5 in situ laryngeal carcinomas, and 32 biopsied laryngeal SCC.

Clinical evaluation was done.

Specimens were formalin-fixed, paraffin-embedded, stained with H&E, classified and graded according to WHO classification, (2005) and immunostained to detect Survivin and Bcl-XL and Bax proteins using the avidin-biotin peroxidase method.

Survivin expression gradually increased significantly with advance of laryngeal carcinoma through the sequence of dysplasia, in situ carcinoma and infiltrating carcinoma (P<0.04).

There is a statistically significant increase in Survivin expression with increasing tumor grade (P<0.03) and with advance in clinical staging (P<0.01).

Regarding lymph node metastasis SVV was more expressed in laryngeal SCC exhibiting lymph node metastasis (P<0.02).

Bax expression was decreased significantly in infiltrating laryngeal carcinoma (P< 0.04) compared with pre-malignant lesions of the larynx.

In contrast, Bcl-XL was increased significantly with the advance of laryngeal carcinoma through dysplasia, carcinoma sequence (P< 0.02).

There was no statistically significant difference in either Bax or Bcl-XL expression considering tumor differentiation, advanced clinical staging or lymph node metastasis.

Conclusion: Survivin plays an important role in the initiation of laryngeal cancer and its progression towards higher grades, invasion and metastasis.

Bax and Bcl-XL play their role early in cancer initiation but have nothing to do as the tumor progresses to higher grades, infiltrates deeply, or giving lymph node metastasis.