Nanoindentation study of the viscoelastic properties of human triple negative breast cancer tissues: Implications for mechanical biomarkers.

This paper presents the results of a combined experimental and theoretical study of the structure and viscoelastic properties of human non-tumorigenic mammary breast tissues and triple negative breast cancer (TNBC) tissues of different histological grades. A combination of immunofluorescence and confocal microscopy, and atomic force microscopy is used to study the actin cytoskeletal structures of non-tumorigenic and tumorigenic breast tissues (grade I to grade III). A combination of nanoindentation and statistical techniques is then used to measure viscoelastic properties of non-tumorigenic and human TNBC of different histological grades. A Standard Fluid Model/Anti-Zener Model II is also used to characterize the viscoelastic properties of the non-tumorigenic and tumorigenic TNBC tissues of different grades. The implications of the results are discussed for the potential application of nanoindentation and statistical deconvolution techniques to the development of mechanical biomarkers for TNBC detection/cancer diagnosis. STATEMENT OF SIGNIFICANCE: There is increasing interest in the development of mechanical biomarkers for cancer diagnosis. Here, we show that nanoindentation techniques can be used to characterize the viscoelastic properties of normal breast tissue and TNBC tissues of different histological grades. The Standard Fluid Model (Anti-Zener Model II) is used to classify the viscoelastic properties of breast tissues of different TNBC histological grades. Our results suggest that breast tissue and TNBC tissue viscoelastic properties can be used as mechanical biomarkers for the detection of TNBC at different stages.

Sustained release of alpha-methylacyl-CoA racemase (AMACR) antibody-conjugated and free doxorubicin from silica nanoparticles for prostate cancer cell growth inhibition.

This article presents silica nanoparticles for the sustained release of AMACR antibody-conjugated and free doxorubicin (DOX) for the inhibition of prostate cancer cell growth. Inorganic MCM-41 silica nanoparticles were synthesized, functionalized with phenylboronic acid groups (MCM-B), and capped with dextran (MCM-B-D). The nanoparticles were then characterized using Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, zeta potential analysis, nitrogen sorption, X-ray diffraction, and thermogravimetric analysis, before exploring their potential for drug loading and controlled drug release. This was done using a model prostate cancer drug, DOX, and a targeted prostate cancer drug, α-Methyl Acyl-CoA racemase (AMACR) antibody-conjugated DOX, which attaches specifically to AMACR proteins that are overexpressed on the surfaces of prostate cancer cells. The kinetics of sustained drug release over 30 days was then studied using zeroth order, first order, second order, Higuchi, and the Korsmeyer-Peppas models, while the thermodynamics of drug release was elucidated by determining the entropy and enthalpy changes. The flux of the released DOX was also simulated using the COMSOL Multiphysics software package. Generally, the AMACR antibody-conjugated DOX drug-loaded nanoparticles were more effective than the free DOX drug-loaded formulations in inhibiting the growth of prostate cancer cells in vitro over a 96 h period. The implications of the results are then discussed for the development of drug-eluting structures for the localized and targeted treatment of prostate cancer.

Adhesion of LHRH/EphA2 to human Triple Negative Breast Cancer tissues.

The adhesive interactions between molecular recognition units (such as specific peptides and antibodies) and antigens or other receptors on the surfaces of tumors are of great value in the design of targeted nanoparticles and drugs for the detection and treatment of specific cancers. In this paper, we present the results of a combined experimental and theoretical study of the adhesion between Luteinizing Hormone Releasing Hormone (LHRH)/Epherin type A2 (EphA2)-AFM coated tips and LHRH/EphA2 receptors that are overexpressed on the surfaces of human Triple Negative Breast Cancer (TNBC) tissues of different histological grades. Following a histochemical and immuno-histological study of human tissue extracts, the receptor overexpression, and their distributions are characterized using Immunohistochemistry (IHC), Immunofluorescence (IF), and a combination of fluorescence microscopy and confocal microscopy. The adhesion forces between LHRH or EphA2 and human TNBC breast tissues are measured using force microscopy techniques that account for the potential effects of capillary forces due to the presence of water vapor. The corresponding adhesion energies are also determined using adhesion theory. The pull off forces and adhesion energies associated with higher grades of TNBC are shown to be greater than those associated with normal/non-tumorigenic human breast tissues, which were studied as controls. The observed increase in adhesion forces and adhesion energies are also correlated with the increasing incidence of LHRH/EphA2 receptors at higher grades of TNBC. The implications of the results are discussed for the development of targeted nanostructures for the detection and treatment of TNBC.

Implementation of and Early Outcomes From Anal Cancer Screening at a Community-Engaged Health Care Facility Providing Care to Nigerian Men Who Have Sex With Men.

PURPOSE: Anal cancer risk is substantially higher among HIV-infected men who have sex with men (MSM) as compared with other reproductive-age adults, but screening is rare across sub-Saharan Africa. We report the use of high-resolution anoscopy (HRA) as a first-line screening tool and the resulting early outcomes among MSM in Abuja, Nigeria. METHODS: From August 2016 to August 2017, 424 MSM enrolled in an anal cancer screening substudy of TRUST/RV368, a combined HIV prevention and treatment cohort. HRA-directed biopsies were diagnosed by histology, and ablative treatment was offered for high-grade squamous intraepithelial lesions (HSIL). HRA proficiency was assessed by evaluating the detection of squamous intraepithelial lesions (SIL) over time and the proportion biopsied. Prevalence estimates of low-grade squamous intraepithelial lesions and HSIL with 95% CIs were calculated. Multinomial logistic regression was used to identify those at the highest risk of SIL. RESULTS: Median age was 25 years (interquartile range [IQR], 22-29), median time since sexual debut was 8 years (IQR, 4-12), and 59% (95% CI, 54.2% to 63.6%) were HIV infected. Rate of detection of any SIL stabilized after 200 screenings, and less than 20% had two or more biopsies. Preliminary prevalence estimates of low-grade squamous intraepithelial lesions and HSIL were 50.0% (95% CI, 44.7% to 55.3%) and 6.3% (95% CI, 4.0% to 9.3%). HIV infection, at least 8 years since anal coital debut, concurrency, and external warts were independently statistically associated with SIL. CONCLUSION: Proficiency with HRA increased with experience over time. However, HSIL detection rates were low, potentially affected by obstructed views from internal warts and low biopsy rates, highlighting the need for ongoing evaluation and mentoring to validate this finding. HRA is a feasible first-line screening tool at an MSM-friendly health care facility. Years since anal coital debut and external warts could prioritize screening.

Expression of some selected cytokeratins and Ki67 protein in prostatic tumor: can these be used as tumor markers.

INTRODUCTION: Diagnosis of prostatic diseases with Immunohistochemistry still faces challenges because of the peculiar histology of the prostate and difference(s) in reactivity of Monoclonal antibodies (MoAb) to benign and malignant changes. METHODS: Thirty (30) archived paraffin embedded tissue samples from primary prostate tumors (15 Benign Prostatic Hyperplasia (BPH) and 15 Cancer of the prostate (CaP)) were sectioned at thickness of 5 µm and confirmed as BPH or CaP. Sections from each sample were stained by Immunohistochemistry using the Streptavidin-biotin method and using CK5/6, CK7, CK8,CK20 and Ki67 antibodies (Zymed Antibody products). Appropriate positive and negative controls for each antibody were setup alongside the test slides. RESULTS: BPH samples were reactive to Ck5/6 (93.3%), Ck7 (80%) and Ck8 (100%). Only 13.3% of BPH samples were reactive to Ki67. The reactivity of Ck5/6, 7, 8 in CaP is a contrast with only 3(20%) of samples positive with Ck5/6, 2(13.3%) positive with Ck7 and 14(93.3%) with Ck8. While reactivity of Ck 8 is similar in BPH and CaP, no reaction was recorded in Ck 20 in both BPH and CaP. Ki67 was only reactive in 2(13.3) of BPH samples and 15(100%) of CaP. Only Ck 8 was expressed in both BPH and CaP. There was co-expression of Ck5/6, 7,8 and Ki67 in 13.3%; Ck7 and Ki67 in 13.3% in both BPH and CaP. CONCLUSION: The various cytokeratins are individually expressed in both BPH and CaP. Ck5/6 and Ck7 are co-expressed and may be used in the diagnosis of BPH, Ck5/6,7,8 and Ki67 are co-expressed in Prostatic adenocarcinoma and squamous cell carcinoma of the prostate while Ck8 and Ki67 are co-expressed and may be used for diagnosis of Prostatic adenocarcinoma alone.

Gene expression of Aurora kinases in prostate cancer and nodular hyperplasia tissues.

OBJECTIVE: To measure the transcript levels of Aurora kinases and compare them to their immunoreactivity patterns in prostate tumors. MATERIALS AND METHODS: A total of 26 cases of prostate cancer (PCa) and 38 cases of benign nodular hyperplasia (BPH) were sampled from archived formalin-fixed paraffin-embedded tissues. Tissue sections were lysed, total RNA extracted and cDNA made by random hexamer priming while slide sections were immunostained for the kinases. Normalized relative quantitation was performed for all the kinases using real-time PCR on TaqMan chemistry. RESULTS: The immunoreactivity profile showed 15.4, 53.8 and 30.7% positivity for Aurora kinases A, B and C in PCa cases, respectively, while the positivity was 76.3, 73.7 and 84.2% for the same kinases in BPH cases. The immunoreactivity was preponderant on epithelial tissue compared to stromal component. CONCLUSION: Aurora kinases were significantly overexpressed in BPH cases compared to PCa cases. At the transcript level, there was no significant differential expression in the kinases between PCa and BPH cases.