Evaluation of the amelioration effect of Ganoderma formosanum extract on delaying PM2.5 damage to lung macrophages.

SCOPE: Particulate matter (PM) contains toxic organic matter and heavy metals that enter the entire body through blood flow and may cause mortality. Ganoderma formosanum mycelium, a valuable traditional Chinese medicine that has been used since ancient times, contains various active ingredients that can effectively impede inflammatory responses on murine alveolar macrophages induced by PM particles. METHODS AND RESULTS: An experimental study assessing the effect of G. formosanum mycelium extract's water fraction (WA) on PM-exposed murine alveolar macrophages using ROS measurement shows that WA reduces intracellular ROS by 12% and increases cell viability by 16% when induced by PM particles. According to RNA-Sequencing, western blotting, and real-time qPCR are conducted to analyze the metabolic pathway. The WA reduces the protein ratio in p-NF-κB/NF-κB by 18% and decreases the expression of inflammatory genes, including IL-1ß by 38%, IL-6 by 29%, and TNF-α by 19%. Finally, the identification of seven types of anti-inflammatory compounds in the WA fraction is achieved through UHPLC-ESI-Orbitrap-Elite-MS/MS analysis. These compounds include anti-inflammatory compounds, namely thiamine, adenosine 5'-monophosphate, pipecolic acid, L-pyroglutamic acid, acetyl-L-carnitine, D-mannitol, and L-malic acid. CONCLUSIONS: The study suggests that the WA has the potential to alleviate the PM -induced damage in alveolar macrophages, demonstrating its anti-inflammatory properties.

Discovery of HDAC6, HDAC8, and 6/8 Inhibitors and Development of Cell-Based Drug Screening Models for the Treatment of TGF-ß-Induced Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis is incurable, and its progression is difficult to control and thus can lead to pulmonary deterioration. Pan-histone deacetylase inhibitors such as SAHA have shown potential for modulating pulmonary fibrosis yet with off-target effects. Therefore, selective HDAC inhibitors would be beneficial for reducing side effects. Toward this goal, we designed and synthesized 24 novel HDAC6, HDAC8, or dual HDAC6/8 inhibitors and established a two-stage screening platform to rapidly screen for HDAC inhibitors that effectively mitigate TGF-ß-induced pulmonary fibrosis. The first stage consisted of a mouse NIH-3T3 fibroblast prescreen and yielded five hits. In the second stage, human pulmonary fibroblasts (HPFs) were used, and four out of the five hits were tested for caco-2 permeability and liver microsome stability to give two potential leads: J27644 (15) and 20. This novel two-stage screen platform will accelerate the discovery and reduce the cost of developing HDAC inhibitors to mitigate TGF-ß-induced pulmonary fibrosis.

Effects of selective cyclooxygenase-2 inhibitor robenacoxib on primary cells derived from feline injection-site sarcoma.

Feline injection-site sarcomas (FISSs) are highly invasive malignant mesenchymal neoplasms that arise from injection sites in cats. Although the tumorigenesis of FISSs is still uncertain, there is a consensus that FISS is associated with chronic inflammation caused by irritation of injection-related trauma and foreign chemical substances. Chronic inflammation can provide a proper microenvironment for tumour development, which has been known as one of the risk factors of tumorigenesis in many tumours. To investigate the tumorigenesis of FISS and screen for its potential therapeutic targets, cyclooxygenase-2 (COX-2), an inflammation-enhancing enzyme, was selected as a target for this study. In vitro experiments using FISS- and normal tissue-derived primary cells and robenacoxib, a highly selective COX-2 inhibitor, were performed. The results demonstrated that expression of COX-2 could be detected in formalin-fixed and paraffin-embedded FISS tissues and FISS-derived primary cells. Cell viability, migration and colony formation of FISS-derived primary cells were inhibited, and cell apoptosis was enhanced by robenacoxib in a dose-dependent manner. However, susceptibility to robenacoxib varied in different lines of FISS primary cells and was not completely correlated with COX-2 expression. Our results suggest that COX-2 inhibitors could be potential adjuvant therapeutics against FISSs.

Neoantigen vaccination augments antitumor effects of anti-PD-1 on mouse hepatocellular carcinoma.

Immune checkpoint inhibitors are groundbreaking resources for cancer therapy. However, only a few patients with hepatocellular carcinoma (HCC) have shown positive responses to anti-PD-1 therapy. Neoantigens are sequence-altered proteins resulting from somatic mutations in cancer. This study identified the neoantigens of Hep-55.1C and Dt81 Hepa1-6 HCCs by comparing their whole exome sequences with those of a normal C57BL/6 mouse liver. Immunogenic long peptides were pooled as peptide vaccines. The vaccination elicited tumor-reactive immune responses in C57BL/6 mice, as demonstrated by IFN-γ ELISPOT and an in vitro killing assay of splenocytes. In the treatment of three mouse HCC models, combined neoantigen vaccination and anti-PD-1 resulted in more significant tumor regression than monotherapies. Flow cytometry of the tumor-infiltrating lymphocytes showed decreased Treg cells and monocytic myeloid-derived suppressor cells, increased CD8+ T cells, enhanced granzyme B expression, and reduced exhaustion-related markers PD-1 and Lag-3 on CD8+ T cells in the combination group. These findings provide a strong rationale for conducting clinical studies of using neoantigen vaccination in combination with anti-PD-1 to treat patients with HCC.

Glycine-rich peptides from fermented Chenopodium formosanum sprout as an antioxidant to modulate the oxidative stress.

Rhizopus oligosporus was utilized in the solid-state fermentation of Chenopodiumformosanumsprouts (FCS) in a bioreactor. Subsequently, the antioxidant activity of food proteins derived from FCS was investigated. Results showed that glycine-rich peptide (GGGGGKP, G-rich peptide), identified from the <2 kDa FCS proteins, had antioxidant values. According to SwissADME, AllerTOP, ToxinPred, and BIOPEP-UWM analyses, G-rich peptide was identified as safe, non-toxic, and non-allergenic. Afterward, the peptide was examined using in silico and in vitro studies to evaluate its potential alleviating oxidative stress caused by particulate matter. This study proposed plausible mechanisms that involve the binding of G-rich peptide which inhibited phosphorylation of the v-rel avian reticuloendotheliosis viral oncogene homologA(RELA) subunit onNF-κB pathway. The inhibition then resulted in down regulation of NF-κB transcription and genetic expression of inflammatory responses. These findings suggested that G-rich peptide from FCS proteins can potentially alleviate oxidative stress.

The Role of Cytokines and Chemokines in Severe Acute Respiratory Syndrome Coronavirus 2 Infections.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in countless infections and caused millions of deaths since its emergence in 2019. Coronavirus disease 2019 (COVID-19)-associated mortality is caused by uncontrolled inflammation, aberrant immune response, cytokine storm, and an imbalanced hyperactive immune system. The cytokine storm further results in multiple organ failure and lung immunopathology. Therefore, any potential treatments should focus on the direct elimination of viral particles, prevention strategies, and mitigation of the imbalanced (hyperactive) immune system. This review focuses on cytokine secretions of innate and adaptive immune responses against COVID-19, including interleukins, interferons, tumor necrosis factor-alpha, and other chemokines. In addition to the review focus, we discuss potential immunotherapeutic approaches based on relevant pathophysiological features, the systemic immune response against SARS-CoV-2, and data from recent clinical trials and experiments on the COVID-19-associated cytokine storm. Prompt use of these cytokines as diagnostic markers and aggressive prevention and management of the cytokine storm can help determine COVID-19-associated morbidity and mortality. The prophylaxis and rapid management of the cytokine storm appear to significantly improve disease outcomes. For these reasons, this study aims to provide advanced information to facilitate innovative strategies to survive in the COVID-19 pandemic.

Thoracic para-aortic lymph node recurrence in patients with esophageal squamous cell carcinoma: A propensity score-matching analysis.

BACKGROUND: Thoracic para-aortic lymph node (TPLN) recurrence in esophageal squamous cell carcinoma (ESCC) is rare and its impact on survival is unknown. We studied survival in patients with ESCC who developed TPLN recurrence. AIM: To study the survival in patients with ESCC who developed TPLNs recurrence. METHODS: Data were collected retrospectively for 219 patients who had undergone curative surgery for ESCC during January 2012 to November 2017 and who developed recurrences (36.29% of 604 patients who had undergone curative surgeries for ESCC). The patients were classified into positive (+) and negative (-) TPLN metastasis subgroups. We also investigated TPLN recurrence in 223 patients with ESCC following definitive chemoradiotherapy during 2012-2013. Following propensity score matching (PSM) and survival estimation, factors predictive of overall survival (OS) were explored using a Cox proportional hazards model. RESULTS: Among the patients with confirmed recurrence, 18 were TPLN (+) and 13 developed synchronous distant metastases. Before PSM, TPLN (+) was associated with worse recurrence-free (P = 0.00049) and OS [vs TPLN (-); P = 0.0027], whereas only the intergroup difference in recurrence-free survival remained significant after PSM (P = 0.013). The Cox analysis yielded similar results. Among the patients who had received definitive chemoradiotherapy, 3 (1.35%) had preoperative TPLN enlargement and none had developed recurrences. CONCLUSION: TPLN metastasis is rare but may be associated with poor survival.

Nanoparticle interactions with immune cells dominate tumor retention and induce T cell-mediated tumor suppression in models of breast cancer.

The factors that influence nanoparticle fate in vivo following systemic delivery remain an area of intense interest. Of particular interest is whether labeling with a cancer-specific antibody ligand ("active targeting") is superior to its unlabeled counterpart ("passive targeting"). Using models of breast cancer in three immune variants of mice, we demonstrate that intratumor retention of antibody-labeled nanoparticles was determined by tumor-associated dendritic cells, neutrophils, monocytes, and macrophages and not by antibody-antigen interactions. Systemic exposure to either nanoparticle type induced an immune response leading to CD8+ T cell infiltration and tumor growth delay that was independent of antibody therapeutic activity. These results suggest that antitumor immune responses can be induced by systemic exposure to nanoparticles without requiring a therapeutic payload. We conclude that immune status of the host and microenvironment of solid tumors are critical variables for studies in cancer nanomedicine and that nanoparticle technology may harbor potential for cancer immunotherapy.

Front-line Therapy in Advanced Non-Small Cell Lung Cancer With Sensitive Epidermal Growth Factor Receptor Mutations: A Network Meta-analysis.

PURPOSE: Several epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) were firmly established as front-line treatment for non-small cell lung cancer (NSCLC) that harbored an activating EGFR mutation. Gefitinib or erlotinib was considered the standard of care. TKI-based combination therapy has been investigated and has shown encouraging results. METHODS: The PubMed and EMBASE databases, the Cochrane Central Register of Controlled Trials, and meeting abstracts were screened for relevant studies between January 2000 and February 2019. Prospective randomized controlled trials were included that investigated EGFR TKIs (alone or in combination) in untreated patients with NSCLC whose tumors had sensitive EGFR mutations. A frequentist random effects network meta-analysis model was conducted to assess objective response rate, progression-free survival, and overall survival. P-score was used to rank treatment effects. FINDINGS: Seventeen trials involving 9 treatments and 4373 patients were included. Heterogeneity existed in the network analysis. For progression-free survival, the top 3 treatments were osimertinib, standard of care plus chemotherapy, and standard of care plus bevacizumab; corresponding p-scores were 0.88, 0.79, and 0.75, respectively. For overall survival, the top 3 treatments were standard of care plus chemotherapy, osimertinib, and dacomitinib; corresponding p-scores were 0.89, 0.85, and 0.64. TKI-based combination therapy caused more toxicity than a TKI alone. IMPLICATIONS: Osimertinib seemed to be a better option as upfront therapy for EGFR-mutant NSCLC in terms of efficacy and tolerability.

First-line checkpoint inhibitors for wild-type advanced non-small-cell cancer: a pair-wise and network meta-analysis.

AIM: To estimate efficacy of checkpoint inhibitors and rank treatment effects in non-small-cell lung cancer. MATERIALS & METHODS: Prospective randomized trials were included. p-score was used to rank treatment effects. RESULTS: A total of nine trials were identified, involving 5504 patients and three checkpoint inhibitors. Pembrolizumab plus chemotherapy had the highest p-score of 0.95 among all the treatments, and was superior to pembrolizumab alone (hazard ratio: 0.87; 95% CI: 0.79-0.95). Combination therapy had more grade 3-5 adverse events; but toxicity-related discontinuation and treatment-related death did not increase. CONCLUSION: Pembrolizumab plus chemotherapy was likely to be the most effective treatment for patients with wild-type advanced NSCLC.

A role for paracrine interleukin-6 signaling in the tumor microenvironment in prostate tumor growth.

BACKGROUND: Interleukin-6 (IL-6) is a mediator of inflammation that can facilitate prostate cancer progression. We previously demonstrated that IL-6 is present in the prostate tumor microenvironment and is restricted almost exclusively to the stromal compartment. The present study examined the influence of paracrine IL-6 signaling on prostate tumor growth using allograft models of mouse prostate cancer (TRAMP-C2), colon cancer (MC38), and melanoma (B16) cell lines in wildtype (WT) and IL-6 knockout (IL-6-/- ) mice. METHODS: Cells were implanted into WT or IL-6-/- mice and tumor sizes were measured at a 3 to 4 day interval. Serum, tumors, and other organs were collected for IL-6 analysis by ELISA and RNA in situ hybridization (RISH). RESULTS: There was a significant reduction in TRAMP-C2 and B16 tumor size grown in IL-6-/- mice versus WT mice (P = 0.0006 and P = 0.02, respectively). This trend was not observed for the MC38 cell line. RISH analysis of TRAMP-C2 tumors grown in WT mice showed that cells present in the tumor microenvironment were the primary source of IL-6 mRNA, not the TRAMP-C2 cells. Serum IL-6 ELISA analyses showed an increase in the circulating levels of IL-6 in WT mice bearing TRAMP-C2 tumors. Similar phospho-STAT3 expression and tumor vascularization were observed in TRAMP-C2 tumors grown in WT and IL-6-/- mice. CONCLUSIONS: Our results are consistent with previous studies in prostate cancer patients demonstrating that paracrine IL-6 production in the tumor microenvironment may influence tumor growth. Additionally, these data provide evidence that elevated systemic IL-6 levels may be involved in tumor growth regulation in prostate cancer, and are not simply caused by or indicative of tumor burden.

A network meta-analysis of nonsmall-cell lung cancer patients with an activating EGFR mutation: Should osimertinib be the first-line treatment?

BACKGROUND: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are the preferred first-line treatment for nonsmall-cell lung cancer (NSCLC) patients with an activating EGFR mutation. Osimertinib, compared with erlotinib or gefitinib, showed an improvement in progression-free survival (PFS) in a recent trial. The authors compared EGFR TKIs in terms of PFS in a network meta-analysis. METHODS: The PubMed and Embase databases and meeting abstracts were screened for relevant studies between January 2009 and November 2017. A random-effect frequentist network meta-analysis model was conducted to assess PFS. P-score was used to rank treatment effects. RESULTS: Eleven trials with 3145 patients and 5 TKIs (gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib) were included. Heterogeneity and inconsistency existed in the network analysis. Gefitinib and erlotinib had similar effects (hazard ratio [HR] 0.94, 95% confidence interval [CI] 0.76-1.15). For all patients, the 3 TKIs with the highest probability of benefit were osimertinib, dacomitinib, and afatinib, with P-scores of 91%, 78%, and 46%, respectively. Compared with erlotinib or gefitinib, osimertinib was associated with improvement in men (HR = 0.79, 95% CI, 0.68-0.92), non-Asians (HR = 0.63, 95% CI, 0.40-0.98), smokers (HR = 0.73, 95% CI, 0.56-0.95), and those with a Del19 mutation (HR = 0.69, 95% CI, 0.54-0.90); dacomitinib and afatinib showed no improvement. Toxicity profiles mostly overlapped in all the EGFR TKIs. Toxicity-related death was rare. CONCLUSIONS: Osimertinib was shown to be the best agent to achieve the longest PFS in NSCLC patients with an activating EGFR mutation. However, the benefit of osimertinib might be restricted to certain subgroups.

Profiling the Urinary Microbiome in Men with Positive versus Negative Biopsies for Prostate Cancer.

PURPOSE: Studies demonstrating bacterial DNA and cultivable bacteria in urine samples have challenged the clinical dogma that urine is sterile. Furthermore, studies now indicate that dysbiosis of the urinary microbiome is associated with pathological conditions. We propose that the urinary microbiome may influence chronic inflammation observed in the prostate, leading to prostate cancer development and progression. Therefore, we profiled the urinary microbiome in men with positive vs negative biopsies for prostate cancer. MATERIALS AND METHODS: Urine was collected from men prior to biopsy for prostate cancer. DNA was extracted from urine pellet samples and subjected to bacterial 16S rDNA Illumina® sequencing and 16S rDNA quantitative polymerase chain reaction. We determined the association between bacterial species and the presence or absence of cancer, cancer grade, and type and degree of prostate inflammation. RESULTS: Urine samples revealed diverse bacterial populations. There were no significant differences in α or ß diversity and no clear hierarchical clustering of benign or cancer samples. We identified a cluster of pro-inflammatory bacteria previously implicated in urogenital infections in a subset of samples. Many species, including known uropathogens, were significantly and differentially abundant among cancer and benign samples, in low vs higher grade cancers and in relation to prostate inflammation type and degree. CONCLUSIONS: To our knowledge we report the most comprehensive study to date of the male urinary microbiome and its relationship to prostate cancer. Our results suggest a prevalence of pro-inflammatory bacteria and uropathogens in the urinary tract of men with prostate cancer.

The complete chloroplast genome sequence of Anoectochilus roxburghii.

The complete chloroplast sequence of the Anoectochilus roxburghii, a popular traditional Chinese medicine for the treatment of cancer, was determined in this study. The chloroplast genome (cpDNA)^ was 152,802 bp in length, containing a pair of inverted repeats of 52,728 bp separated by a large single-copy region and a small single-copy region of 82,641 bp and 17,433 bp, respectively. The chloroplast genome encodes 116 predicted functional genes, including 81 protein-coding genes, four ribosomal RNA genes, and 31 transfer RNA genes, 25 of which are duplicated in the inverted repeat regions. The cpDNA is GC-rich (36.9%).

A Paracrine Role for IL6 in Prostate Cancer Patients: Lack of Production by Primary or Metastatic Tumor Cells.

Correlative human studies suggest that the pleiotropic cytokine IL6 contributes to the development and/or progression of prostate cancer. However, the source of IL6 production in the prostate microenvironment in patients has yet to be determined. The cellular origin of IL6 in primary and metastatic prostate cancer was examined in formalin-fixed, paraffin-embedded tissues using a highly sensitive and specific chromogenic in situ hybridization (CISH) assay that underwent extensive analytical validation. Quantitative RT-PCR showed that benign prostate tissues often had higher expression of IL6 mRNA than matched tumor specimens. CISH analysis further indicated that both primary and metastatic prostate adenocarcinoma cells do not express IL6 mRNA. IL6 expression was highly heterogeneous across specimens and was nearly exclusively restricted to the prostate stromal compartment--including endothelial cells and macrophages, among other cell types. The number of IL6-expressing cells correlated positively with the presence of acute inflammation. In metastatic disease, tumor cells were negative in all lesions examined, and IL6 expression was restricted to endothelial cells within the vasculature of bone metastases. Finally, IL6 was not detected in any cells in soft tissue metastases. These data suggest that, in prostate cancer patients, paracrine rather than autocrine IL6 production is likely associated with any role for the cytokine in disease progression.

Bacterial Prostatitis Enhances 2-Amino-1-Methyl-6-Phenylimidazo[4,5-b]Pyridine (PhIP)-Induced Cancer at Multiple Sites.

Dietary carcinogens, such as 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), and chronic inflammation have each been implicated as etiologic agents in prostate cancer. We hypothesized that bacterial prostatitis would accelerate PhIP-induced preinvasive lesions in the rat prostate. Male Fischer 344 rats were assigned into 4 groups: Control (untreated), PhIP (200 ppm in the diet for 20 weeks), Escherichia coli (E. coli, prostatic inoculation in week 10), or PhIP + E. coli. Study animals were monitored for a total of 52 weeks and were euthanized as necessary based on strict criteria for health status and tumor burden. Animals treated with E. coli initially developed acute and chronic inflammation in all lobes of the prostate, whereas inflammation was observed predominantly in the ventral lobe at time of death. PhIP + E. coli-treated animals exhibited a marked decrease in survival compared with PhIP-alone-treated animals as a result of an increase in the number of invasive cancers that developed at multiple sites, including the skin, small intestine, and Zymbal's gland. Despite their earlier mortality, PhIP + E. coli-treated animals developed an increased average number of precancerous lesions within the prostate compared with PhIP-treated animals, with a significantly increased Ki-67 index. Multiplexed serum cytokine analysis indicated an increase in the level of circulating IL6 and IL12 in PhIP + E. coli-treated animals. Elevated serum IL6 levels correlated with the development of precancerous lesions within the prostate. These results suggest that bacterial infections and dietary carcinogens, two conceivably preventable cancer risk factors, may synergistically promote tumorigenesis.

Tumorigenicity of hypoxic respiring cancer cells revealed by a hypoxia-cell cycle dual reporter.

Although aerobic glycolysis provides an advantage in the hypoxic tumor microenvironment, some cancer cells can also respire via oxidative phosphorylation. These respiring ("non-Warburg") cells were previously thought not to play a key role in tumorigenesis and thus fell from favor in the literature. We sought to determine whether subpopulations of hypoxic cancer cells have different metabolic phenotypes and gene-expression profiles that could influence tumorigenicity and therapeutic response, and we therefore developed a dual fluorescent protein reporter, HypoxCR, that detects hypoxic [hypoxia-inducible factor (HIF) active] and/or cycling cells. Using HEK293T cells as a model, we identified four distinct hypoxic cell populations by flow cytometry. The non-HIF/noncycling cell population expressed a unique set of genes involved in mitochondrial function. Relative to the other subpopulations, these hypoxic "non-Warburg" cells had highest oxygen consumption rates and mitochondrial capacity consistent with increased mitochondrial respiration. We found that these respiring cells were unexpectedly tumorigenic, suggesting that continued respiration under limiting oxygen conditions may be required for tumorigenicity.

Systemic diphenidol reduces neuropathic allodynia and TNF-alpha overexpression in rats after chronic constriction injury.

Diphenidol has been shown to block voltage-gated Na(+) channels, which are associated with specific types of pain. Here, we evaluated the effects of diphenidol on chronic constriction injury (CCI)-evoked allodynia and expression of tumor necrosis factor-α (TNF-α). A peripheral nerve injury was elicited in rats by placing four loosely constrictive ligatures around the sciatic nerve. After intraperitoneal injection of diphenidol, rats were tested for evidence of mechanical allodynia prior to surgery, and on postoperative days 3, 6, 7, 11, 13 and 14. We showed that CCI rats received diphenidol caused dose-dependent increases in mechanical withdrawal threshold. Both diphenidol 2 and 10 µmol/kg groups, but not 0.4 µmol/kg diphenidol, displayed lower TNF-α level in the sciatic nerve than the CCI group (P<0.05) on day 7 after CCI. Our results support the conclusion that systemic diphenidol produced a dose-related inhibition of mechanical allodynia following chronic constriction injury of the sciatic nerve. This antiallodynic effect is related to the decrease of TNF-α expression in the sciatic nerve of CCI rats.

A mouse model of chronic prostatic inflammation using a human prostate cancer-derived isolate of Propionibacterium acnes.

BACKGROUND: Prostatic inflammation has been linked to a number of prostatic diseases such as benign prostatic hyperplasia (BPH), prostatitis syndromes, and prostate cancer. Major unanswered questions include what pathogenic mechanisms, such as bacterial infections, may drive the accumulation of inflammatory infiltrates in the human prostate, and how inflammation might contribute to disease. To study this potential link in an in vivo system, we developed a mouse model of long-term bacteria-induced chronic inflammation of the prostate using a human prostatectomy-derived strain of Propionibacterium acnes. METHODS: C57BL/6J mice were inoculated, via urethral catheterization, with vehicle control or a prostatectomy-derived strain of P. acnes (PA2). Animals were assessed at 2 days, 1, 2, or 8 weeks post-inoculation via histology and immunohistochemistry (IHC). RESULTS: PA2 inoculation resulted in severe acute and chronic inflammation confined to the dorsal lobe of the prostate. Chronic inflammation persisted for at least 8 weeks post-inoculation. Inflammatory lesions were associated with an increase in the Ki-67 proliferative index, and diminished Nkx3.1 and androgen receptor (AR) production. Interestingly, the observed response required live bacteria and both IHC and in situ hybridization assays for P. acnes indicated a potential intracellular presence of P. acnes in prostate epithelial cells. CONCLUSIONS: To our knowledge, this is the first mouse model of long-term prostatic inflammation induced by P. acnes, and more generally, any prostatectomy-derived bacterial isolate. This model may serve as a valuable preclinical model of chronic prostatic inflammation that can be used to mechanistically study the link between inflammation and prostatic disease.

Multilocus sequence typing (MLST) analysis of Propionibacterium acnes isolates from radical prostatectomy specimens.

BACKGROUND: Inflammation is commonly observed in radical prostatectomy specimens, and evidence suggests that inflammation may contribute to prostate carcinogenesis. Multiple microorganisms have been implicated in serving as a stimulus for prostatic inflammation. The pro-inflammatory anaerobe, Propionibacterium acnes, is ubiquitously found on human skin and is associated with the skin disease acne vulgaris. Recent studies have shown that P. acnes can be detected in prostatectomy specimens by bacterial culture or by culture-independent molecular techniques. METHODS: Radical prostatectomy tissue samples were obtained from 30 prostate cancer patients and subject to both aerobic and anaerobic culture. Cultured species were identified by 16S rDNA gene sequencing. Propionibacterium acnes isolates were typed using multilocus sequence typing (MLST). RESULTS: Our study confirmed that P. acnes can be readily cultured from prostatectomy tissues (7 of 30 cases, 23%). In some cases, multiple isolates of P. acnes were cultured as well as other Propionibacterium species, such as P. granulosum and P. avidum. Overall, 9 of 30 cases (30%) were positive for Propionibacterium spp. MLST analyses identified eight different sequence types (STs) among prostate-derived P. acnes isolates. These STs belong to two clonal complexes, namely CC36 (type I-2) and CC53/60 (type II), or are CC53/60-related singletons. CONCLUSIONS: MLST typing results indicated that prostate-derived P. acnes isolates do not fall within the typical skin/acne STs, but rather are characteristic of STs associated with opportunistic infections and/or urethral flora. The MLST typing results argue against the likelihood that prostatectomy-derived P. acnes isolates represent contamination from skin flora.