Aberrant Collagen Cross-linking in Human Oral Squamous Cell Carcinoma

Tumor progression is a complex process involving extracellular matrix (ECM) remodeling and stiffening. However, the mechanisms that govern these processes and their roles in tumor progression are still poorly understood. In this study, we performed bioinformatics, immunohistochemical, and biochemical analyses to examine if collagen cross-linking is associated with tumor stage and regional lymph node metastasis (RLNM) in oral squamous cell carcinoma (OSCC). We found that the genes encoding key enzymes for cross-linking are frequently overexpressed in oral, head, and neck cancers. Specifically, the enzymes lysyl hydroxylase 2 (LH2) or lysyl oxidase (LOX) and LOX-like 2 (LOXL2) were significantly upregulated in late-stage tumors and associated with poor patient prognosis. The protein levels of these enzymes in the primary human OSCC were also significantly increased in late-stage tumors and markedly elevated in the RLNM-positive tumors. Notably, while overall LOX/LOXL2-catalyzed collagen cross-links were enriched in late-stage and RLNM-positive tumors, LH2-mediated stable cross-links were significantly increased. To our knowledge, this is the first study to investigate the association of collagen cross-linking and expression of key enzymes regulating this process with OSCC stage. The data indicate a critical role for collagen cross-linking in OSCC tumor progression and metastasis, which may provide insights into development of novel therapeutic strategies to prevent OSCC progression.

Cholestasis in newborn infants with perinatal asphyxia

OBJECTIVE

The aim of this study was to characterize the liver involvement in infants who have both neonatal asphyxia and neonatal cholestasis.

METHODS

We describe four asphyctic newborn infants (three born at term) who developed early (age 3.8 +/- 2.1 days) intrahepatic neonatal cholestasis and in whom tests for causes of neonatal liver damage were negative.

RESULTS

The clinical picture and course were benign and similar to that of sporadic "idiopathic" neonatal hepatitis. Clinical signs and abnormal liver function tests tended to normalize within the first year of life in all. Conjugated bilirubin became normal at 6 months after the onset of cholestasis, while liver enzymes tended towards normal values thereafter, within 1 year of follow-up. Liver biopsy (taken in one patient) showed a typical picture of giant cell hepatitis; ultrastructure was nonspecific.

SIGNIFICANCE

Our results suggest that isolated asphyxia should be taken into account as a potential causal factor in term or pre-term asphyctic newborns who develop early "idiopathic" neonatal cholestasis.