MSH2-deficient prostate tumours have a distinct immune response and clinical outcome compared to MSH2-deficient colorectal or endometrial cancer

BACKGROUND

Recent publications have shown patients with defects in the DNA mismatch repair (MMR) pathway driven by either MSH2 or MSH6 loss experience a significant increase in the incidence of prostate cancer. Moreover, this increased incidence of prostate cancer is accompanied by rapid disease progression and poor clinical outcomes.

METHODS AND RESULTS

We show that androgen-receptor activation, a key driver of prostate carcinogenesis, can disrupt the MSH2 gene in prostate cancer. We screened tumours from two cohorts (recurrent/non-recurrent) of prostate cancer patients to confirm the loss of MSH2 protein expression and identified decreased MSH2 expression in recurrent cases. Stratifying the independent TCGA prostate cancer cohort for MSH2/6 expression revealed that patients with lower levels of MSH2/6 had significant worse outcomes, in contrast, endometrial and colorectal cancer patients with lower MSH2/6 levels. MMRd endometrial and colorectal tumours showed the expected increase in mutational burden, microsatellite instability and enhanced immune cell mobilisation but this was not evident in prostate tumours.

CONCLUSIONS

We have shown that loss or reduced levels of MSH2/MSH6 protein in prostate cancer is associated with poor outcome. However, our data indicate that this is not associated with a statistically significant increase in mutational burden, microsatellite instability or immune cell mobilisation in a cohort of primary prostate cancers.

Transcriptome sequencing and multi-plex imaging of prostate cancer microenvironment reveals a dominant role for monocytic cells in progression

BACKGROUND

Prostate cancer is caused by genomic aberrations in normal epithelial cells, however clinical translation of findings from analyses of cancer cells alone has been very limited. A deeper understanding of the tumour microenvironment is needed to identify the key drivers of disease progression and reveal novel therapeutic opportunities.

RESULTS

In this study, the experimental enrichment of selected cell-types, the development of a Bayesian inference model for continuous differential transcript abundance, and multiplex immunohistochemistry permitted us to define the transcriptional landscape of the prostate cancer microenvironment along the disease progression axis. An important role of monocytes and macrophages in prostate cancer progression and disease recurrence was uncovered, supported by both transcriptional landscape findings and by differential tissue composition analyses. These findings were corroborated and validated by spatial analyses at the single-cell level using multiplex immunohistochemistry.

CONCLUSIONS

This study advances our knowledge concerning the role of monocyte-derived recruitment in primary prostate cancer, and supports their key role in disease progression, patient survival and prostate microenvironment immune modulation.

Loss of SNAI2 in Prostate Cancer Correlates With Clinical Response to Androgen Deprivation Therapy

PURPOSE

Androgen receptor (AR) signaling is important in prostate cancer progression, and therapies that target this pathway have been the mainstay of treatment for advanced disease for over 70 years. Tumors eventually progress despite castration through a number of well-characterized mechanisms; however, little is known about what determines the magnitude of response to short-term pathway inhibition.

METHODS

We evaluated a novel combination of AR-targeting therapies (degarelix, abiraterone, and bicalutamide) and noted that the objective patient response to therapy was highly variable. To investigate what was driving treatment resistance in poorly responding patients, as a secondary outcome we comprehensively characterized pre- and post-treatment samples using both whole-genome and RNA sequencing.

RESULTS

We find that resistance following short-term treatment differs molecularly from typical progressive castration-resistant disease, associated with transcriptional reprogramming, to a transitional epithelial-to-mesenchymal transition (EMT) phenotype rather than an upregulation of AR signaling. Unexpectedly, tolerance to therapy appears to be the default state, with treatment response correlating with the prevalence of tumor cells deficient for SNAI2, a key regulator of EMT reprogramming.

CONCLUSION

We show that EMT characterizes acutely resistant prostate tumors and that deletion of SNAI2, a key transcriptional regulator of EMT, correlates with clinical response.

Hot topics in interventional cardiology: Proceedings from the society for cardiovascular angiography and interventions 2020 think tank

The society for cardiovascular angiography and interventions (SCAI) think tank is a collaborative venture that brings together interventional cardiologists, administrative partners, and select members of the cardiovascular industry community for high-level field-wide discussions. The 2020 think tank was organized into four parallel sessions reflective of the field of interventional cardiology: (a) coronary intervention, (b) endovascular medicine, (c) structural heart disease, and (d) congenital heart disease (CHD). Each session was moderated by a senior content expert and co-moderated by a member of SCAI's emerging leader mentorship program. This document presents the proceedings to the wider cardiovascular community in order to enhance participation in this discussion, create additional dialogue from a broader base, and thereby aid SCAI and the industry community in developing specific action items to move these areas forward.

Detection of ctDNA in plasma of patients with clinically localised prostate cancer is associated with rapid disease progression

BACKGROUND

DNA originating from degenerate tumour cells can be detected in the circulation in many tumour types, where it can be used as a marker of disease burden as well as to monitor treatment response. Although circulating tumour DNA (ctDNA) measurement has prognostic/predictive value in metastatic prostate cancer, its utility in localised disease is unknown.

METHODS

We performed whole-genome sequencing of tumour-normal pairs in eight patients with clinically localised disease undergoing prostatectomy, identifying high confidence genomic aberrations. A bespoke DNA capture and amplification panel against the highest prevalence, highest confidence aberrations for each individual was designed and used to interrogate ctDNA isolated from plasma prospectively obtained pre- and post- (24 h and 6 weeks) surgery. In a separate cohort (n = 189), we identified the presence of ctDNA TP53 mutations in preoperative plasma in a retrospective cohort and determined its association with biochemical- and metastasis-free survival.

RESULTS

Tumour variants in ctDNA were positively identified pre-treatment in two of eight patients, which in both cases remained detectable postoperatively. Patients with tumour variants in ctDNA had extremely rapid disease recurrence and progression compared to those where variants could not be detected. In terms of aberrations targeted, single nucleotide and structural variants outperformed indels and copy number aberrations. Detection of ctDNA TP53 mutations was associated with a significantly shorter metastasis-free survival (6.2 vs. 9.5 years (HR 2.4; 95% CIs 1.2-4.8, p = 0.014).

CONCLUSIONS

CtDNA is uncommonly detected in localised prostate cancer, but its presence portends more rapidly progressive disease.

Loss of SNAI2 in prostate cancer and effect on patient response to androgen deprivation therapy

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Background: Androgen receptor (AR) signalling is important in prostate cancer progression, and therapies that specifically target this pathway are the mainstay of treatment for advanced disease. Treatment however is non-curative, and resistance develops inevitably with time. Although the mechanisms that drive castration resistant disease have been intensively analysed, how tumours survive and persist during the initial pathway inhibition is unclear. Methods: To track this process in detail we performed a Phase II neo-adjuvant study of a novel combination of AR targeting therapies (degarelix & abiraterone & bicalutamide) for 6 months prior to prostatectomy in men with high risk, localised disease. To determine what was driving tumour persistence in poorly responding patients, we comprehensively characterised pre- and post-treatment samples using both whole genome and RNA-sequencing, validating pertinent findings by qRT-PCR, IHC and FISH. Results: Despite universal ‘biochemical responses’, objective responses to treatment as measured by residual tumours volumes were highly variable. This state which we term ‘castration-persistence’, is molecularly distinct from ‘castration-resistance’, and is characterised by global transcriptional reprogramming leading to a transitional EMT state. Whole genome sequencing confirms tumour persistence is not associated with the emergence of a ‘driver’ lesion, rather treatment response is associated with regression of a ‘treatment sensitive’ subclonal population, defined by deletion of the EMT master regulator SNAI2. The extent of treatment response observed was determined by the prevalence of cells with loss of SNAI2 in pre-treatment biopsies. Conclusions: Cell plasticity with transition to a mesenchymal phenotype defines prostate cancer cell survival to acute AR signalling inhibition. Tumour response is determined by the proportion of cells present harbouring defects in this program.

Androgen deprivation therapy promotes an obesity-like microenvironment in periprostatic fat

Prostate cancer is a leading cause of morbidity and cancer-related death worldwide. Androgen deprivation therapy (ADT) is the cornerstone of management for advanced disease. The use of these therapies is associated with multiple side effects, including metabolic syndrome and truncal obesity. At the same time, obesity has been associated with both prostate cancer development and disease progression, linked to its effects on chronic inflammation at a tissue level. The connection between ADT, obesity, inflammation and prostate cancer progression is well established in clinical settings; however, an understanding of the changes in adipose tissue at the molecular level induced by castration therapies is missing. Here, we investigated the transcriptional changes in periprostatic fat tissue induced by profound ADT in a group of patients with high-risk tumours compared to a matching untreated cohort. We find that the deprivation of androgen is associated with a pro-inflammatory and obesity-like adipose tissue microenvironment. This study suggests that the beneficial effect of therapies based on androgen deprivation may be partially counteracted by metabolic and inflammatory side effects in the adipose tissue surrounding the prostate.

Developments in oligometastatic hormone-sensitive prostate cancer

PURPOSE

To review the current understanding and recent developments regarding the concept of oligometastases in hormone-sensitive prostate cancer.

METHODS

A comprehensive literature search of electronic databases, including PubMed and Embase was conducted for the search term 'oligometastases' in combinations with 'prostate cancer', 'hormone sensitive', 'genetics', and 'molecular'. All articles relating to these search terms have been taken into account.

RESULTS

Prostate cancer remains a major cause of morbidity and mortality worldwide. The majority of these cancer-related deaths result from metastases. Currently, there is a dichotomy in prostate cancer management where it is only deemed curable if it is localized, while any signs of metastasis relegate patients to systemic therapies to delay their inevitable death. A growing body of evidence supports the notion that aggressive treatments during the stable 'oligometastatic' state can have significant clinical benefits and potentially 'reset' prostate cancer to an earlier time point in cancer progression. This concept of oligometastases has been adopted in other cancer settings such as colorectal and non-small-cell lung cancers.

CONCLUSION

Multiple clinical and molecular biological studies have been influential in the support of a stable state in metastatic cancer progression coined 'oligometastases'. As our understanding of oligometastases in hormone-sensitive prostate cancer develops, we will be able to molecularly define the oligometastatic state and develop clinically available diagnostic tests. In doing so, prostate cancer patients will experience significant clinical benefits and the burden of prostate cancer worldwide will likely be reduced.

Investigating the global dispersal of chickens in prehistory using ancient mitochondrial DNA signatures

Data from morphology, linguistics, history, and archaeology have all been used to trace the dispersal of chickens from Asian domestication centers to their current global distribution. Each provides a unique perspective which can aid in the reconstruction of prehistory. This study expands on previous investigations by adding a temporal component from ancient DNA and, in some cases, direct dating of bones of individual chickens from a variety of sites in Europe, the Pacific, and the Americas. The results from the ancient DNA analyses of forty-eight archaeologically derived chicken bones provide support for archaeological hypotheses about the prehistoric human transport of chickens. Haplogroup E mtDNA signatures have been amplified from directly dated samples originating in Europe at 1000 B.P. and in the Pacific at 3000 B.P. indicating multiple prehistoric dispersals from a single Asian centre. These two dispersal pathways converged in the Americas where chickens were introduced both by Polynesians and later by Europeans. The results of this study also highlight the inappropriate application of the small stretch of D-loop, traditionally amplified for use in phylogenetic studies, to understanding discrete episodes of chicken translocation in the past. The results of this study lead to the proposal of four hypotheses which will require further scrutiny and rigorous future testing.

Ultra-high throughput screen of two-million-member combinatorial compound collection in a miniaturized, 1536-well assay format

Results of a complete survey of the more than 2-million-member Pharmacopeia compound collection in a 1536-well microvolume screening assay format are reported. A complete technology platform, enabling the performance of ultra-high throughput screening in a miniaturized 1536-well assay format, has been assembled and utilized. The platform consists of tools for performing microvolume assays, including assay plates, liquid handlers, optical imagers, and data management software. A fluorogenic screening assay for inhibition of a protease enzyme target was designed and developed using this platform. The assay was used to perform a survey screen of the Pharmacopeia compound collection for active inhibitors of the target enzyme. The results from the survey demonstrate the successful implementation of the ultra-high throughout platform for routine screening purposes. Performance of the assay in the miniaturized format is equivalent to that of a standard 96-well assay, showing the same dependence on kinetic parameters and ability to measure enzyme inhibition. The survey screen identified an active class of compounds within the Pharmacopeia compound collection. These results were confirmed using a standard 96-well assay.

Commitment to physical activity and anxiety about physique among college women

This study involved a comparison of scores on the Commitment to Physical Activity Scale and the Social Physique Anxiety Scale by 258 women athletes, kinesiology majors, and a control group. Mean commitment to physical activity of the control group was significantly lower than the means of the other groups; the mean on anxiety about social physique was significantly higher.

Experience with rapid latex agglutination testing for group A streptococcal pharyngitis in a pediatric group office laboratory

We evaluated 2401 patients with suspected streptococcal pharyngitis with the Culturette 10-minute Group A Strep ID test during a 6-month period in order to determine its suitability for rapid diagnosis in a busy private office practice. Duplicate throat swabs were obtained for each child, and latex agglutination was performed within 15 minutes. In children with negative latex agglutination results, the second swab was cultured. All latex agglutination results were available within 20 minutes of collection, while the patients waited in the office. Seven hundred thirty-eight specimens were positive by latex agglutination. Seventy-eight of the 1663 latex negative specimens contained group A streptococci on culture (sensitivity 90 percent). Approximately 60 percent of these latex-negative, culture-positive specimens demonstrated 3(+)-4+ growth in culture, unlike previous studies ascribing false-negative latex results to low colony count specimens. Fifty percent of bacitracin-susceptible streptococci tested were not group A, indicating a relatively high occurrence of nongroup A beta-hemolytic streptococcal carriage in this patient population. The use of latex agglutination for detection of group A streptococcal pharyngitis was well-suited to our office practice, even during an extremely busy winter season. Although this assay appears to have a relatively high sensitivity, it is still prudent to culture latex-negative swabs to exclude group A streptococcal infection. The significance of nongroup A beta-hemolytic streptococci in our patient population was unclear. Further refinements are necessary.

Establishment of a human cutaneous T-cell lymphoma in C.B-17 SCID mice

Investigation into the immunobiology of cutaneous T-cell lymphomas (CTCL) would be facilitated by the development of a suitable experimental system. The recent use of mice with severe combined immune deficiency (SCID) as a vehicle to study the human immune system prompted us to try to establish CTCL in SCID mice. We found that a CD4+ lymphocytic infiltrate characteristic of CTCL was maintained within patient skin grafts in place on natural killer cell depleted SCID mice for the month of observation. CTCL cells were not found outside the human skin graft. This chimeric model using SCID mice and patient lesional skin should provide a useful tool to characterize CTCL/skin microenvironmental interactions and to test new therapeutic approaches.

Group F streptococci in the pharynx: pathogens or innocent bystanders?

beta-Hemolytic streptococci (BHS) of Lancefield group F were isolated in moderate to heavy growth from throat cultures taken from 46 children and adolescents with symptomatic pharyngitis. In most instances, oxygen deprivation by means of an anaerobe jar was required for these beta-hemolytic organisms to grow. In relation to a comparison group of children with throat cultures positive for group A BHS, children with group F isolates were more likely to be adolescents and less likely to have fever and cervical adenopathy. It appears that group F BHS are not a major cause of nonepidemic pharyngitis in the pediatric age group. More precise determination of how commonly these organisms cause pharyngitis will require either comparison of isolation rates of group F BHS from the throats of both sick and well children, or further elucidation of the serologic response to these organisms so as to distinguish invasive infection from asymptomatic carriage.

Rapid diagnosis of streptococcal pharyngitis in two pediatric offices using a latex agglutination kit

The diagnostic accuracy and practicality of a latex agglutination test for the rapid diagnosis of streptococcal pharyngitis directly from throat swabs were evaluated in two private pediatric practices. Compared with anaerobic throat culture the latex agglutination method had a sensitivity of 93.4%, a specificity of 90.2% and an overall accuracy of 91.8%. Even used as a while-you-wait test, the rapid method fit easily into the routine of busy office practice. Latex agglutination testing for the rapid diagnosis of streptococcal pharyngitis may prove to be a valuable adjunct to the office microbiology laboratory.

Effect of atmosphere of incubation on the isolation of group A streptococci from throat cultures

The optimal atmosphere of incubation for the isolation of group A beta-hemolytic streptococci from throat cultures has been the subject of considerable debate. To resolve this issue, we examined 5992 consecutive throat cultures performed at a private pediatric office in children with acute upper respiratory tract infections. All throat cultures were streaked onto duplicate blood agar plates, one of which was then incubated anaerobically and the other aerobically. beta-Hemolytic streptococci were isolated in cultures from 1885 (31.5%) of the patients; 1479 (24.7%) were identified as group A, and 406 (6.8%) were identified as non-group A. Group A streptococci were recovered significantly more often from the plates incubated anaerobically than from those incubated aerobically (1467 vs. 1054; anaerobic only, 425; aerobic only, 12; P less than 0.01). Non-group A streptococci were also recovered significantly more often from the plates incubated anaerobically than from the plates incubated aerobically (397 vs. 170; anaerobic only, 236; aerobic only, 9;P less than 0.01). Anaerobic incubation maximizes the yield of the throat culture. The additional cost and effort of anaerobic incubation are small, and would appear to be justified by the increased isolation rate of group A beta-hemolytic streptococci. The significance of the increased isolation rate of non-group A beta-hemolytic streptococci with anaerobic incubation needs to be investigated further.

Experience with the microbiologic diagnosis of Campylobacter enteritis in an office laboratory

Campylobacter jejuni has been recognized as a frequent cause of bacterial diarrhea in infants and children. C. jejuni is a fastidious, Gram-negative, comma-shaped or sea gull-shaped, curved rod which is capable, particularly during the summer months, of causing slimy mucoid, blood diarrhea, abdominal pain and fever. In our pediatric office laboratory we found over a 12-month period that 14 (10%) of 126 stool specimens contained this pathogen. All but two children were diagnosed during the late spring and summer. There was no common source for Campylobacter infections in the patients. In 8 (66%) of 12 patients, C. jejuni infection was immediately detected by examining a 1% aqueous basic fuchsin-stained stool smear. Uncontrolled observations from this study suggest that erythromycin therapy, if started within 2 to 3 days of the onset of illness, is clinically effective.