Hyaluronidase and CD44 hyaluronan receptor expression in squamous cell laryngeal carcinoma

Squamous cell laryngeal carcinoma undergoes significant structural-related modifications of the extracellular matrix components (ECM), the most characteristics being the presence of degraded collagen, aggrecan and hyaluronan. We examined the presence of hyaluronidase and of the cellular hyaluronan receptor CD44 during the various stages of cancer. ECM components were extracted by using PBS, 4 M GdnHCl and 4 M GdnHCl-0.1% Triton-X 100 sequentially and hyaluronidase and CD44 analyzed by zymography and immunochemistry techniques. Total RNA was also extracted and the mRNA of the various hyaluronidases and of CD44 was analyzed after amplification with RT-PCR. Hyaluronidase was detected as a double band of 45 and 55 kDa molecular mass, only in cancer samples. The analysis of mRNA indicated an aberrant expression of PH-20, the testicular-type hyaluronidase, at late stages of cancer and an overexpression of HYAL1 only at stage IV. In addition, CD44 was identified in two protein bands of 80 and 64 kDa in cancer samples. The analysis of mRNA showed that hyaluronan receptor was expressed in a stage-related order. Thus, it could be suggested that in laryngeal squamous cell carcinoma, cancer cells migrated and proliferated under the influence of small molecular mass hyaluronan, by expressing increased amounts of its receptor.