Pathohistological features of the aging human lacrimal gland.

AIM: To assess sex-related differences in the pathohistological features of the human lacrimal gland and to investigate age-related and sex-related differences in stereologically measured volume density of the secretory tissue, connective tissue, and fat. METHODS: We performed an observational analysis of acinar atrophy, periacinar fibrosis, periductal fibrosis, ductal dilation, ductal proliferation, fatty infiltration, and lymphocyte infiltration of hematoxylin and eosin-stained lacrimal gland samples from 81 cornea donors. Stereological analysis of the volume density of the secretory tissue, connective tissue, and fat was performed on samples from 66 donors. RESULTS: Up to 69% of all samples showed degenerative changes. Female samples had a higher frequency of all observed degenerative changes, except ductal dilation. While acinar atrophy was significantly more prevalent in women, ductal dilation was significantly more prevalent in men. Stereological analysis indicated lower portions of acini and higher portions of connective tissue and fat, as well as a more pronounced age-related progression of degenerative changes in female samples. CONCLUSION: Female lacrimal glands are more susceptible to degeneration, and this susceptibility could play an important role in the higher incidence of dry eye disease in older women. A further stereological analysis using more samples from younger age groups is needed to elucidate age-related and sex-related differences in the structure of the human lacrimal gland and their impact on dry eye disease.

Necrotic Cells from Head and Neck Carcinomas Release Biomolecules That Are Activating Toll-like Receptor 3.

Tumor necrosis is a recurrent characteristic of head and neck squamous cell carcinomas (HNSCCs). There is a need for more investigations on the influence of biomolecules released by these necrotic foci in the HNSCC tumor microenvironment. It is suspected that a fraction of the biomolecules released by necrotic cells are damage-associated molecular patterns (DAMPs), which are known to be natural endogenous ligands of Toll-like receptors (TLRs), including, among others, proteins and nucleic acids. However, there has been no direct demonstration that biomolecules released by HNSCC necrotic cells can activate TLRs. Our aim was to investigate whether some of these molecules could behave as agonists of the TLR3, either in vitro or in vivo. We chose a functional approach based on reporter cell exhibiting artificial TLR3 expression and downstream release of secreted alkaline phosphatase. The production of biomolecules activating TLR3 was first investigated in vitro using three HNSCC cell lines subjected to various pronecrotic stimuli (external irradiation, serum starvation, hypoxia and oxidative stress). TLR3 agonists were also investigated in necrotic tumor fluids from five oral cancer patients and three mouse tumor grafts. The release of biomolecules activating TLR3 was demonstrated for all three HNSCC cell lines. External irradiation was the most consistently efficient stimulus, and corresponding TLR3 agonists were conveyed in extracellular vesicles. TLR3-stimulating activity was detected in the fluids from all five patients and three mouse tumor grafts. In most cases, this activity was greatly reduced by RNAse pretreatment or TLR3 blocking antibodies. Our data indicate that TLR3 agonists are consistently present in necrotic fluids from HNSCC cells and mainly made of dsRNA fragments. These endogenous agonists may induce TLR3, which might lead to a protumorigenic effect. Regarding methodological aspects, our study demonstrates that direct investigations-including functional testing-can be performed on necrotic fluids from patient tumors.

Expression of Androgen and Estrogen Receptors in the Human Lacrimal Gland.

Lacrimal gland dysfunction causes dry eye disease (DED) due to decreased tear production. Aqueous-deficient DED is more prevalent in women, suggesting that sexual dimorphism of the human lacrimal gland could be a potential cause. Sex steroid hormones are a key factor in the development of sexual dimorphism. This study aimed to quantify estrogen receptor (ER) and androgen receptor (AR) expression in the human lacrimal gland and compare it between sexes. RNA was isolated from 35 human lacrimal gland tissue samples collected from 19 cornea donors. AR, ERα, and ERß mRNA was identified in all samples, and their expression was quantified using qPCR. Immunohistochemical staining was performed on selected samples to evaluate protein expression of the receptors. ERα mRNA expression was significantly higher than the expression of AR and ERß. No difference in sex steroid hormone (SSH) receptor mRNA expression was observed between sexes, and no correlation was observed with age. If ERα protein expression is found to be concordant with mRNA expression, it should be investigated further as a potential target for hormone therapy of DED. Further research is needed to elucidate the role of sex steroid hormone receptors in sex-related differences of lacrimal gland structure and disease.

Immunotherapy for Uveal Melanoma - Current Knowledge and Perspectives.

Uveal melanoma is the most prevalent primary intraocular tumour in adults with the incidence between five and six cases per million people in the United States and Europe. The prognosis of patients with uveal melanoma is unfavourable with a 5-year survival rate of 50-70% despite significant advances in local tumour treatment using radiotherapy or surgical resection. Approximately 50% of the patients develop metastases within 15 years from initial diagnosis, mostly in the liver. The median survival rate after the onset of metastases is 6 months. Potential treatment options for metastatic uveal melanoma are chemotherapy, targeted therapy, and immunotherapy but no method showed satisfactory results. Immunotherapy with checkpoint inhibition showed promising results in the treatment of cutaneous melanoma; however, it did not appear to be equally effective with uveal melanoma. This may be due to differences in mutational burden, expression of neoantigens between these two types of tumour, immunosuppressive tumour microenvironment, and low immunogenicity and immune privilege of uveal melanoma. Considering the disappointing results of treatment with anti-CTLA-4 and PD-1/PD-L1 blockade in patients with advanced uveal melanoma several new forms of therapies are being developed. This may include immunotherapy with IMCgp100, glembatumumab vedotin and the infusion of autologous TILs, targeted therapy with selective MEK inhibitors, epigenetic therapy, and nanotherapy. Better insight into the molecular and genetic profile of uveal melanoma will facilitate detection of new prognostic biomarkers and thus enable a better modification of the existing immunotherapy methods and development of new forms of treatment specifically designed for uveal melanoma patients.