JAK1/2 pathway inhibition suppresses M2 polarization and overcomes resistance of myeloma to lenalidomide by reducing TRIB1, MUC1, CD44, CXCL12, and CXCR4 expression

Monocytes polarize into pro-inflammatory macrophage-1 (M1) or alternative macrophage-2 (M2) states with distinct phenotypes and physiological functions. M2 cells promote tumour growth and metastasis whereas M1 macrophages show anti-tumour effects. We found that M2 cells were increased whereas M1 cells were decreased in bone marrow (BM) from multiple myeloma (MM) patients with progressive disease (PD) compared to those in complete remission (CR). Gene expression of Tribbles homolog 1 (TRIB1) protein kinase, an inducer of M2 polarization, was increased in BM from MM patients with PD compared to those in CR. Ruxolitinib (RUX) is an inhibitor of the Janus kinase family of protein tyrosine kinases (JAKs) and is effective for treating patients with myeloproliferative disorders. RUX markedly reduces both M2 polarization and TRIB1 gene expression in MM both in vitro and in vivo in human MM xenografts in severe combined immunodeficient mice. RUX also downregulates the expression of CXCL12, CXCR4, MUC1, and CD44 in MM cells and monocytes co-cultured with MM tumour cells; overexpression of these genes is associated with resistance of MM cells to the immunomodulatory agent lenalidomide. These results provide the rationale for evaluation of JAK inhibitors, including MM BM in combination with lenalidomide, for the treatment of MM patients.

What determines gender inequalities in social capital in Ukraine?

Background

Social capital is a social determinant of health that has an impact on equity and well-being. It may be unequally distributed among any population. The aims of this study are to investigate the distribution of different forms of social capital between men and women in Ukraine and analyse how potential gender inequalities in social capital might be explained and understood in the Ukrainian context.

Method

The national representative cross-sectional data from the European Social Survey (wave 6) was used with a sample of 1377 women and 797 men. Seven outcomes that represent cognitive and structural social capital were constructed i.e. institutional trust, generalised trust, reciprocity, safety, as well as bonding, bridging and linking forms. Multivariate logistic regression and post-regression Fairlies decompositions were used for the analyses.

Results

There are several findings that resulted from the analyses i), access to institutional trust, linking and bridging social capital is very limited; ii), the odds for almost all forms of social capital (besides safety) are lower for men; iii), feeling about income and age explain most of the gender differences and act positively, as well as offsetting the differences.

Conclusion

Social capital is unequally distributed between different population groups. Some forms of social capital have a stronger buffering effect on women than on men in Ukraine. Reducing gender and income inequalities would probably influence the distribution of social capital within the society.

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There is a limited access to institutional trust, linking and bridging social capital.

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The odds for almost all forms of social capital are lower for men (besides safety).

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Feeling about income and age explain most of the gender differences.

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Feeling about income and age offset most of the gender differences.

Prognostic Utility of a Whole-blood Androgen Receptor-based Gene Signature in Metastatic Castration-resistant Prostate Cancer

BACKGROUND

The treatment paradigm for metastatic castration-resistant prostate cancer (mCRPC) has evolved significantly in recent years. Identifying predictive and/or prognostic biomarkers in the context of this rapidly expanding therapeutic armamentarium remains a pressing and unmet clinical need.

OBJECTIVE

To develop a prognostic whole-blood gene signature for mCRPC patients.

DESIGN, SETTING, AND PARTICIPANTS

As part of an ongoing prospective, multicentre biomarker research study (Australian Prostate Biomarker Alliance), we enrolled 115 mCRPC patients commencing chemotherapy (n = 34) or androgen receptor (AR) pathway inhibitors therapy (n = 81) and obtained pretreatment whole-blood samples in PAXgene RNA tubes. Gene expression was assessed using reverse transcription-polymerase chain reaction.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Gene transcripts correlating with overall survival (OS) at p < 0.10 in univariate Cox regression models were incorporated into a multigene signature. Kaplan-Meier survival estimates and multivariate analyses were used to assess association with clinical outcomes. Prognostic strength of the signature was estimated using a concordance probability estimate (CPE).

RESULTS AND LIMITATIONS

Based on univariate analysis for OS, the following genes were incorporated into a multigene signature: AR splice variant 7 (AR-V7), and three androgen-regulated genes: GRHL2, HOXB13, and FOXA1. The number of positive transcripts clearly stratified survival outcomes (median OS: not reached vs 24.8 mo vs 16.2 mo for 0, 1, and ≥2 transcripts, respectively; p = 0.0052). Notably, this multigene signature retained prognostic significance on multivariable analysis (hazard ratio, 2.1; 95% confidence interval, 1.1-4.0; p = 0.019). Moreover, CPE for this model was 0.78, indicating strong discriminative capacity. Limitations include short follow-up time.

CONCLUSIONS

Our data demonstrate the prognostic utility of a novel whole-blood AR-based signature in mCRPC patients commencing contemporary systemic therapies. Our pragmatic assay requires minimal processing, can be performed in most hospital laboratories, and could represent a key prognostic tool for risk stratification in mCRPC.

PATIENT SUMMARY

We found that expression of certain genes associated with the androgen receptor could help determine how long men with advanced prostate cancer survive after starting modern drug therapies.

Expression of Androgen Receptor Splice Variant 7 or 9 in Whole Blood Does Not Predict Response to Androgen-Axis-targeting Agents in Metastatic Castration-resistant Prostate Cancer

In 2014, a landmark study was published demonstrating that the expression of androgen receptor splice variant (AR-V) 7 was a negative predictive biomarker for response to abiraterone acetate and enzalutamide in metastatic castration-resistant prostate cancer (mCRPC) patients. However, these results were not supported by the recently reported ARMOR3-SV phase III clinical trial, which employed an identical circulating tumour cell assay to assess AR-V7 expression. Therefore, the predictive utility of AR-V7 expression in mCRPC remains uncertain, as does any potential association between other AR-Vs and treatment response. To further investigate, we designed a highly sensitive and specific whole blood assay for detecting AR-V7 and AR-V9. We then examined for a correlation between baseline AR-V7/V9 status and treatment outcome in 37 mCRPC patients commencing abiraterone or enzalutamide. Of the patients, 24% (9/37) were AR-V-positive. Notably, prostate-specific antigen (PSA) response rates did not significantly differ between AR-V-positive (6/9) and AR-V-negative (18/28) patients (66% vs 64%, p=0.9). Likewise, median PSA progression-free survival was not significantly different between AR-V-positive and AR-V-negative patients (9.2 mo vs not reached; p=0.9). These data, which support the findings of the pivotal ARMOR3-SV clinical trial, suggest that baseline AR-V expression does not predict outcomes in mCRPC patients receiving abiraterone or enzalutamide.

PATIENT SUMMARY

Detection of androgen receptor splice variants (AR-Vs) in circulating tumour cells of advanced prostate cancer patients has been linked to resistance to abiraterone and enzalutamide. We designed a blood test to detect AR-Vs that can be performed more routinely than tests involving circulating tumour cells and found that patients with AR-Vs still benefit from these effective treatments.

Whole blood FOLH1 mRNA expression and treatment response in metastatic castration-resistant prostate cancer (mCRPC)

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Background: Identifying predictive biomarkers for mCRPC patients receiving androgen receptor signalling inhibitors (ARSI) or chemotherapy remains an unmet clinical need. FOLH1 encodes for Prostate-Specific Membrane Antigen (PSMA), a type II glycoprotein highly expressed on prostate cancer cells. We designed a whole blood assay to detect FOLH1 mRNA, and correlated expression with clinical outcomes in patients commencing ARSI (abiraterone or enzalutamide) or chemotherapy (docetaxel or cabazitaxel). Methods: mCRPC patients commencing ARSI or chemotherapy were prospectively recruited at three Australian centres from June 2016 to July 2018. A quantitative reverse transcription polymerase chain reaction assay was used to detect FOLH1 transcript from whole blood samples collected in PAXgene® RNA tubes. Pre-treatment FOLH1 expression was correlated with PSA response rate (Fisher’s exact test) and PSA progression-free survival (PSA-PFS) (log-rank test). Results: Median follow-up was 13.6 months (IQR 9.7–19.3). In total, 88 pre-treatment samples were analysed, of which 75 (85%) were FOLH1-positive. In patients receiving ARSI, outcomes favoured FOLH1-positive patients compared to FOLH1-negative patients, with higher PSA response rates (39/60, 65% vs. 2/7, 29%; p = 0.1) and longer PSA-PFS (median 9.0 months [95% CI, 7.2-10.8] vs. 2.8 months [95% CI, 2.3-3.3]; p = 0.03). Conversely, in chemotherapy-treated patients, inferior outcomes were observed in FOLH1-positive patients compared to FOLH1-negative patients, with lower PSA response rates (4/15, 27% vs. 5/6, 83%, p = 0.05) and shorter PSA-PFS (median 2.9 months [95% CI, 2.8-3.0] vs. 4.1 months [95% CI, 3.7-4.5]; p = 0.32). Conclusions: Pre-treatment FOLH1 expression may differentiate between outcomes on ARSI vs. chemotherapy in mCRPC patients. The utility of FOLH1 as a predictive biomarker in mCRPC warrants further evaluation in larger, independent cohorts. [Table: see text]

Abstract A098: Whole blood assay for rapid detection of AR-v7 in metastatic castration-resistant prostate cancer: No correlation with response to androgen-axis targeting agents

Background: The expression of AR-v7 in circulating tumor cells (CTCs) of mCRPC patients potentially confers treatment resistance to AR-axis targeting agents, though recent data from the ARMOR3-SV study as well as other publications challenge this hypothesis. Due to the potential barriers of developing a reliable CTC platform, our aim was to develop a rapid assay for AR-v7 detection in patient whole blood samples.

Method: We created and optimized a whole blood quantitative real-time polymerase chain reaction assay to correlate outcomes of patients on AR-axis targeting agents with expression of AR-v7. The expression of AR-v7 mRNA in whole blood from 47 patients with mCRPC was obtained prior to commencing therapy. Each sample was run in triplicate; positivity was defined as at least two replicates reaching cycle threshold within a standard deviation between cycles of ≤ 0.25. Gene expression was correlated with PSA response rate using Fisher’s exact test.

Results: In our cohort, 10 of 47 patients (21%) were AR-v7+. Of patients commencing abiraterone or enzalutamide (37/47 patients, 79%), we observed similar response rates in the AR-v7+ (4/7) patients, compared to the AR-v7 (20/30) patients (57% vs. 66%, P=0.63; Fisher’s exact test). In two patients, early onset of acquired resistance was associated with conversion from AR-v7 to AR-v7+. AR-v7 was not detected in any of the 13 normal male controls.

Conclusion: We developed a specific assay for AR-v7 detection in whole blood from mCRPC patients. Similar PSA response rates were seen in AR-v7+ and AR-v7 patients, inconsistent with literature characterizing AR-v7 as a predictive biomarker, but in support of ARMOR3-SV data demonstrating moderate response rates to an AR-axis targeting agent in AR-v7+ patients. Future directions will include cohort expansion, interrogation of other AR variants, and examination of other clinically meaningful endpoints.

Citation Format: Sarah To, Edmond Kwan, Heidi Fettke, Maria Docanto, Nicole Ng, Andrew Mant, Phillip Parente, Carmel Pezaro, Lisa Horvath, Lisa Graham, Tilman Todenhofer, Arun Azad. Whole blood assay for rapid detection of AR-v7 in metastatic castration-resistant prostate cancer: No correlation with response to androgen-axis targeting agents [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A098.

Abstract 2593: AR-V7 and AR-V9 expression is not predictive of response to AR-axis targeting agents in metastatic castration-resistant prostate cancer

In 2014, a landmark study was published demonstrating that androgen receptor splice variant (AR-V) AR-V7 expression was a negative predictive biomarker for response to abiraterone acetate and enzalutamide in metastatic castration-resistant prostate cancer (mCRPC) patients. However, these results were not supported by the recently reported ARMOR3-SV phase III clinical trial, which employed an identical circulating tumor cell assay to assess AR-V7 expression. Therefore, the predictive utility of AR-V7 expression in mCRPC remains uncertain, as does any potential association between other AR splice variants and treatment response. To further investigate, we designed a highly sensitive and specific whole blood assay for detecting AR-V7 and AR-V9. We then examined for a correlation between baseline AR-V7/V9 status and treatment outcome in 37 mCRPC patients commencing abiraterone or enzalutamide. Blood was taken in a PAXgene RNA tube at baseline prior to the commencement of therapy and at end of treatment (if applicable). 24% (9/37) of patients were AR-V-positive. Notably, PSA response rates did not significantly differ between AR-V-positive (6/9) and AR-V-negative (18/28) patients (66% vs. 64%, p=0.896). Likewise, median PSA progression-free survival was not significantly different between AR-V-positive and AR-V-negative patients (9.2 months vs. not reached; p=0.894). Additionally, we identified 2 patients who were AR-V7 negative at baseline but had converted to AR-V7 positive in their end-of-treatment sample. This was associated with much shorter PSA-PFS than those that remained negative (2.58 months vs. no reached), suggesting gain of AR-V expression may be a marker of acquired resistance. These data, which support the findings of the pivotal ARMOR3-SV clinical trial, suggest that baseline AR-V expression does not predict outcomes in mCRPC patients receiving abiraterone or enzalutamide.

Citation Format: Sarah Q. To, Edmond Kwan, Heidi Fettke, Andrew Mant, Maria Docanto, Luciano Martelotto, Patricia Bukczynska, Nicole Ng, Lisa-Jane Graham, Phillip Parente, Carmel Pezaro, Kate Mahon, Lisa Horvath, Tilman Todenhöfer, Arun Azad. AR-V7 and AR-V9 expression is not predictive of response to AR-axis targeting agents in metastatic castration-resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2593.

Systematic study of constraints imposed by modified nucleoside triphosphates with protein-like side chains for use in in vitro selection

Successful selection of modified DNAzymes depends on the potential for modified nucleoside triphosphates (dNTPs) to replace their unmodified counterparts in enzyme catalyzed primer extension reactions and, once incorporated, to serve as template bases for information transfer prior to PCR amplification. To date, the most densely modified DNAzymes have been selected from three modified dNTPs: 8-histaminyl-deoxyadenosine (dA^imTP), 5-guanidinoallyl-deoxyuridine (dU^gaTP), and 5-aminoallyl-deoxycytidine (dC^aaTP) to provide several RNA-cleaving DNAzymes with greatly enhanced rate constants compared to unmodified counterparts. Here we report biophysical and enzymatic properties of these three modified nucleosides in the context of specific oligonucleotide sequences to understand how these three modified nucleobases function in combinatorial selection. The base-pairing abilities of oligonucleotides bearing one or three modified nucleosides were investigated by thermal denaturation studies and as templates for enzymatic polymerization with both modified and unmodified dNTPs. While we address certain shortcomings in the use of modified dNTPs, we also provide key evidence of faithful incorporation and enzymatic read-out, which strongly supports their continued use in in vitro selection.

Whole blood AR-V7 and AR-V9 mRNA expression and treatment response in metastatic castrate-resistant prostate cancer (mCRPC)

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Background: Androgen receptor splice variant (AR-V) expression has previously been regarded as a negative predictive biomarker for response to abiraterone and enzalutamide in mCRPC patients. However, recent data questions this association. We designed a whole blood assay to detect AR-V7 and AR-V9, the two most abundantly expressed AR-Vs, and correlated expression with clinical outcomes in patients commencing abiraterone or enzalutamide. Methods: We developed a quantitative real-time polymerase chain reaction assay to detect AR-V7 and AR-V9 from whole blood collected in PAXgene tubes. The assay was applied to samples prospectively collected from 37 mCRPC patients prior to commencing abiraterone or enzalutamide, and at treatment cessation. Patients positive for either AR-V7 or AR-V9 were defined as AR-V-positive, and AR-V-negative if neither variant was detected. AR-V expression was correlated with PSA response rate (chi-square test) and PSA progression-free survival (PSA-PFS) (log-rank test). Assay sensitivity was determined by serially diluting RNA from VCaP prostate cancer cells (known to express AR-V7) to establish a lower limit of detection. Results: The median follow-up was 7.29 months (IQR 4.21-10.55); 9 of 37 patients (24%) were AR-V-positive. We observed similar response rates in AR-V-positive (6/9) and AR-V-negative (18/28) patients (66% vs. 64%, p = 0.896). PSA-PFS did not differ significantly between groups (9.2 months vs. not reached, p = 0.355). Two patients converted from AR-V-negative to AR-V-positive (PSA-PFS 3.35 and 0.60 months respectively), and one patient remained AR-V-positive at baseline and end-of-treatment sampling. The lower limit of detection for AR-V7 was 0.1%, and AR-V7/V9 was not detected in any of the 13 normal male controls. Conclusions: We developed a sensitive and specific whole blood assay for AR-V7 and AR-V9 detection in patients with mCRPC. Neither PSA response rates nor PSA-PFS differed significantly between AR-V-positive and AR-V-negative patients. These data support recent literature questioning the role of AR-V expression as a negative predictive biomarker in mCRPC patients receiving abiraterone or enzalutamide.

Differentiating mouse embryonic stem cells express markers of human endometrium

BACKGROUND

Modeling early endometrial differentiation is a crucial step towards understanding the divergent pathways between normal and ectopic endometrial development as seen in endometriosis.

METHODS

To investigate these pathways, mouse embryonic stem cells (mESCs) and embryoid bodies (EBs) were differentiated in standard EB medium (EBM). Immunofluorescence (IF) staining and reverse-transcription polymerase chain reaction (RT-PCR) were used to detect expression of human endometrial cell markers on differentiating cells, which were sorted into distinct populations using fluorescence-activated cell sorting (FACS).

RESULTS

A subpopulation (50%) of early differentiating mESCs expressed both glandular (CD9) and stromal (CD13) markers of human endometrium, suggestive of a novel endometrial precursor cell population. We further isolated a small population of endometrial mesenchymal stem cells, CD45-/CD146+/PDGFR-β+, from differentiating EBs, representing 0.7% of total cells. Finally, quantitative PCR demonstrated significantly amplified expression of transcription factors Hoxa10 and Foxa2 in CD13+ EBs isolated by FACS (p = 0.03).

CONCLUSIONS

These findings demonstrate that mESCs have the capacity to express human endometrial cell markers and demonstrate potential differentiation pathways of endometrial precursor and mesenchymal stem cells, providing an in vitro system to model early endometrial tissue development. This model represents a key step in elucidating the mechanisms of ectopic endometrial tissue growth. Such a system could enable the development of strategies to prevent endometriosis and identify approaches for non-invasive monitoring of disease progression.

The value of FDG-PET in the staging of gastric adenocarcinoma: A single institution retrospective review

BACKGROUND

The value of FDG-PET in the staging of gastric adenocarcinoma (GA) has been subject to debate.

METHODS

We performed a retrospective review of GA patients between 2006 and 2014 and identified those who had a CT and FDG-PET before initiating treatment. CT and FDG-PET images were analyzed by a blinded body radiologist and nuclear physician, respectively. Disease stage was assessed, looking at primary tumor (PT), locoregional (LLN) and distant lymph node disease (DLN), and metastasis (M).

RESULTS

We identified 608 patients who had biopsy-proven GA and 207 (34.0%) had a CT and FDG-PET as part of their staging work-up. Of these, imaging from 166 (27.3%) patients was available for review. CT identified PT, LLN, DLN, and M in 120 (72.3%), 84 (50.6%), 25 (15.1%), and 32 (19.3%) patients, respectively; while FDG-PET identified PT, LLN, DLN, and M in 125 (75.3%), 78 (47.0%), 41 (24.7%), and 27 (16.3%) of patients, respectively. FDG-PET up-staged 31 (18.7%) patients while it down-staged 17 (10.2%) patients. Of patients who were up-staged, 20 (64.5%) developed progressive disease.

CONCLUSIONS

Our findings support the use of FDG-PET as a valuable adjunct to CT in the staging of GA, as it changed the stage in 48 (28.9%) patients. J. Surg. Oncol. 2016;113:640-646. © 2016 Wiley Periodicals, Inc.