Selective expression of lysyl oxidase (LOX) in the stromal reactions of broncho-pulmonary carcinomas

Lysyl oxidase (LOX) is the extracellular enzyme that initiates the main pathway of collagen and elastin cross-linking. LOX has also been correlated with the ras recision gene, a putative tumour suppressor isolated from revertants of ras-transformed fibroblasts. The present study investigates the potential correlation of LOX-dependent matrix protein cross-linking in the stromal reaction of lung carcinomas, with reference to the architecture of the main stromal reactions accompanying the neoplastic breast tissues. A strong LOX expression was associated with the hypertrophic scar-like stromal reaction found at the front of tumour progression in squamous carcinomas, adenocarcinomas, large cell carcinomas, or at sites of initial extense in bronchiolo-alveolar carcinomas. In contrast, little or no LOX expression was found within the stromal reaction of invasive carcinomas, small cell carcinomas, and neuro-endocrine carcinomas. The significance of LOX expression and of the stromal reaction are discussed, in light of data that associate LOX expression with tumours displaying a rather good prognosis.