Abstract 2922: Loss of retinoblastoma protein dysregulates HIF1-mediated genetic programs, and promotes tumor cell invasiveness and neuroendocrine differentiation in prostate cancer cells

Loss of tumour suppressor proteins, such as the retinoblastoma protein (Rb), results in tumour progression and metastasis. Metastasis is facilitated by low oxygen availability within the tumour that is detected by hypoxia inducible factors (HIFs). The HIF1 complex, HIF1α and its dimerization partner the aryl hydrocarbon receptor nuclear translocator (ARNT), is the master regulator of the hypoxic response. Previously, we demonstrated that Rb represses the transcriptional response to hypoxia by virtue of its association with HIF1. In this report, we further characterized the role of Rb in HIF1-regulated genetic programs by stably ablating Rb expression with retrovirally-introduced short hairpin RNA in LNCaP and 22rV1 human prostate cancer cells. DNA microarray analysis revealed that Rb regulates specific chromosomal gene clusters and loss of Rb in conjunction with hypoxia leads to dysregulation of HIF1-regulated genetic programs that promote cell invasion and neuroendocrine differentiation. Gene ontology analysis of the hypoxia-inducible genes sensitive to loss of Rb revealed that a significant portion of these genes are involved in neuroendocrine differentiation (NED), specifically ENO2, KISS1R and HTR5A. ENO2 is the bonafide marker of neuroendocrine differentiation and it's presence is a signature of late stage castrate resistant prostate cancer. Furthermore, we have functional evidence KISS1R is linked to intracellular calcium mobilization in 22RV1 cells. We have demonstrated that increased expression of HIF-regulated genes in response to loss of Rb activates Akt and ERK signaling pathways and promotes neuroendocrine differentiation and invasion. Inhibition of these signaling pathways significantly decreased actin polymerization in LNCaP cells. For the first time, we have established a direct link between hypoxic tumour environments, Rb inactivation and progression to late stage metastatic neuroendocrine prostate cancer. Understanding the molecular pathways responsible for progression of benign prostate tumours to metastasized and lethal forms will aid in the development of more effective prostate cancer therapies.

Citation Format: Mark Labrecque, Mandeep Takhar, Rebecca J. Nason, Stephanie Santacruz, Kevin Tam, Shabnam Massah, Anne Haegert, Robert Bell, Manuel Altamirano-Dimas, Colin Collins, Frank Lee, Gratien Prefontaine, Michael Cox, Timothy Beischlag. Loss of retinoblastoma protein dysregulates HIF1-mediated genetic programs, and promotes tumor cell invasiveness and neuroendocrine differentiation in prostate cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2922.

Clinical evaluation of Acuvue contact lenses with UV blocking characteristics

BACKGROUND

In response to increasing scientific evidence which indicates that ultraviolet radiation (UVR) is a potential threat to ocular health, Acuvue contact lenses (Vistakon, Johnson & Johnson Vision Products Inc., Jacksonville, Florida) have been developed which incorporate an ultraviolet (UV) blocker within the lens polymer. Data are presented for the first clinical evaluation of Acuvue lenses with UV blocking characteristics.

METHOD

A double-masked, multicenter, prospective clinical trial involving 94 subjects was conducted. The study followed a randomized, parallel group design and consisted of 3 months of daily wear with two-weekly lens replacement. Two thirds of the subjects (61) wore the test lenses (Acuvue with UV blocker) and the remaining subjects (33) wore conventional Acuvue lenses (without UV blocker).

RESULTS

Biomicroscopic evaluations indicated that the performance of the test and control lenses was clinically similar. No clinically relevant differences between the test and control lenses were noted in the subjective assessments of vision, comfort, or handling. In addition, no differences were shown for surface deposition, lens durability, visual acuity, and subjective symptoms.

CONCLUSION

The study findings indicate that the addition of a UV blocker to Acuvue contact lenses has been achieved without affecting daily wear clinical performance. Because there is increasing evidence to suggest that the ocular tissues may be damaged by UVR, it is prudent for eye care practitioners to prescribe contact lenses that offer the benefits of both regular replacement and UV protection.

A 3-year prospective study of the clinical performance of daily disposable contact lenses compared with frequent replacement and conventional daily wear contact lenses

PURPOSE

To determine the clinical performance of daily disposable contact lens wear compared to conventional daily wear contact lenses and frequent replacement contact lenses.

METHODS

This 3-year prospective study was conducted in 12 U.S. practices. Of 338 eligible subjects enrolled (126 conventional daily wear, 144 frequent replacement, and 68 daily disposable), 229 subjects disposable group were compared with the conventional daily wear group and two sub-groups of frequent replacement subjects: (a) those with replacement at 2-weak intervals and (b) those with replacement at 1 or 3 months.

RESULTS

Comparing the daily disposable and conventional daily wear groups, the daily disposable subjects were more likely to be asymptomatic, reported fewer symptoms of redness, cloudy vision and grittiness/dirty sensation, reported better vision and overall satisfaction, and had fewer lens surface deposits, complications, tarsal abnormalities, and unscheduled visits, while conventional daily wear subjects reported better lens handling. Comparing the daily disposable and frequent replacement (1/3 months) groups, daily disposable subjects reported fewer symptoms of foreign body sensation, redness, cloudy vision and grittiness/dirty sensation, reported better subjective vision, comfort and overall satisfaction, and has fewer lens surface deposits, complications, and tarsal abnormalities, while frequent replacement (1/3 months) subjects reported fewer dryness symptoms and better lens handling. Comparing the daily disposable and frequent replacement (2-weeks) groups, daily disposable subjects reported better subjective vision and overall satisfaction and had fewer lens surface deposits and tarsal abnormalities, while frequent replacement (2-weeks) subjects reported fewer photophobia symptoms.

CONCLUSIONS

The results indicate that daily disposable wear may be the most trouble-free way of wearing contact lenses.

Multisite comparison of contact lens modalities. Daily disposable wear vs. conventional daily wear in successful contact lens wearers

BACKGROUND

RESULTS are reported for the first year of one facet of an ongoing multisite clinical investigation. In this article, one subpopulations of subjects wearing soft contact lenses on a daily disposable wear schedule (DDW is compared to a second subpopulation wearing lenses on a conventional daily wear (CDW) basis.

METHODS

All subjects recruited were successfully wearing lenses on a conventional daily wear basis at the time of enrollment. In addition to an initial visit, follow-up visits occurred at 1, 4, 12, 26 and 52 weeks. Areas of assessment included vision, comfort, ocular health, subject-reported symptoms, lens surface deposits and overall satisfaction. A total of 70 subjects were dispensed lenses on a daily disposable schedule and 125 subjects were dispensed lenses on a conventional daily wear schedule.

RESULTS

Five DDW subjects and 15 CDW subjects discontinued before the 52-week follow-up visit. When the findings of the 52-week follow-up visit were compared, the DDW group performed significantly better than the CDW group in the following areas: Snellen visual acuity, subjective vision and comfort assessment, symptomatology, lens deposits and overall satisfaction. In addition, while performance levels tended to improve in the DDW group when the results from the 52-week follow-up visit were compared with the 1-week follow-up visit, they tended to decline in the CDW group over this period of time. Subjects wearing lenses on a daily disposable basis were significantly less likely to report for an unscheduled visit than subjects wearing lenses on a conventional wear basis, with the DDW subjects reporting with less serious ocular health problems.

CONCLUSIONS

Patients who were wearing conventional reusable daily wear lenses and refit into lens wear on a daily disposable basis realized clinically significant advantages compared to a similar population of patients who were refit with lenses worn on a conventional daily wear basis.

A clinical evaluation of frequent replacement contact lenses on patients currently wearing premium reusable daily wear soft contact lenses

A 3-month clinical investigation was undertaken to evaluate a population of premium reusable daily wear soft contact lens wearers when refitted with soft contact lenses worn on a daily wear schedule and replaced every 2 weeks. In addition to an initial visit, follow-up visits occurred at 2-, 4-, 8-, and 12 weeks. Areas of assessment included vision, lens fitting performance, ocular physiology, subjective comfort and handling responses and lens surface deposits and damage. Of the 51 patients recruited, 50 were successfully trial fit and enrolled. During the course of the investigation, all subjects utilized a multipurpose care regimen without the addition of an enzymatic cleaner. Upon conclusion of the investigation, 75.0 percent of the subjects chose to continue wearing the study lenses on a 2-week frequent replacement basis.