Distinct roles and molecular mechanisms of nicotine and benzo(a)pyrene in ferroptosis of lung adenocarcinoma and lung squamous cell carcinoma.

INTRODUCTION: The essence of ferroptosis is the accumulation of membrane lipid peroxides caused by increased iron, which disrupts the redox balance within cells and triggers cell death. Abnormal metabolism of iron significantly increases the risk of lung cancer and induces treatment resistance. However, the roles and mechanisms of smocking in ferroptosis in patients with lung cancer are still unclear. METHODS: Our study was a secondary bioinformatics analysis followed by an experimental cell culture analysis. In this study, we identified the different ferroptosis-related genes and established the signature in lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD) patients with different smocking status, based on The Cancer Genome Atlas (TCGA) database. Fanyl diphosphate fanyl transferase 1 (FDFT1) in LUSC patients and solute carrier one family member 5 (SLC1A5) in LUAD patients were confirmed to be related to ferroptosis. Next, we checked the roles of two main components of smoke, nicotine, and benzo(a)pyrene (BaP), in ferroptosis of non-small-cell lung cancer (NSCLC) cells. RESULTS: We confirmed that nicotine inhibited reactive oxygen species (ROS) levels and induced glutathione peroxidase (GPX4) expression, while the opposite roles of BaP were observed in NSCLC cells. Mechanically, nicotine protected NSCLC cells from ferroptosis through upregulation of epidermal growth factor receptor (EGFR) and SLC1A5 expression. BaP-induced ferroptosis in NSCLC cells depends on FDFT1 expression. CONCLUSIONS: In this study, the ferroptosis-associated gene signature was identified in LUAD and LUSC patients with different smoking status. We confirmed nicotine-protected LUAD and LUSC cells from ferroptosis by upregulating EGFR and SLC1A5 expression. BaP-induced ferroptosis in these cells depends on FDFT1 expression.

Insurance Approval for Laparoscopic Sleeve Gastrectomy in Adolescents in the Midsouth.

Background: Metabolic and bariatric surgery (MBS) has been shown to be safe and effective for the treatment of adolescent obesity, yet many providers express hesitance to refer adolescents for surgery due to concerns for insufficient insurance coverage. Methods: The Healthy Lifestyle Clinic, a pediatric weight management clinic, was established in 2014, and an adolescent MBS program was added in 2017. Patients 15 years or older who meet the selection criteria are eligible for the surgery track. A retrospective chart review was conducted to describe our experience obtaining insurance approval for laparoscopic sleeve gastrectomy (LSG) for our adolescent patients. Results: Almost all patients who were interested in and eligible for LSG ultimately received insurance approval. Most patients had public insurance (70%). Sixty-four percent of patients were approved after the initial application, 23% were approved after a peer-to-peer review, and 11% required an appeal for approval. There was no difference in the time from insurance application to insurance approval based on age, race/ethnicity, or type of insurance. Conclusions: Age <18 years and having public health insurance have not been demonstrated as barriers to insurance approval for LSG in our cohort. Providers should not delay referral for MBS for eligible adolescents based on concern for insufficient insurance coverage. Adolescent MBS programs would benefit from a patient advocate to help families navigate the insurance approval process and reduce barriers to surgery.

Cancer-cell-secreted extracellular vesicles target p53 to impair mitochondrial function in muscle.

Skeletal muscle loss and weakness are associated with bad prognosis and poorer quality of life in cancer patients. Tumor-derived factors have been implicated in muscle dysregulation by inducing cachexia and apoptosis. Here, we show that extracellular vesicles secreted by breast cancer cells impair mitochondrial homeostasis and function in skeletal muscle, leading to decreased mitochondrial content and energy production and increased oxidative stress. Mechanistically, miR-122-5p in cancer-cell-secreted EVs is transferred to myocytes, where it targets the tumor suppressor TP53 to decrease the expression of TP53 target genes involved in mitochondrial regulation, including Tfam, Pgc-1α, Sco2, and 16S rRNA. Restoration of Tp53 in muscle abolishes mitochondrial myopathology in mice carrying breast tumors and partially rescues their impaired running capacity without significantly affecting muscle mass. We conclude that extracellular vesicles from breast cancer cells mediate skeletal muscle mitochondrial dysfunction in cancer and may contribute to muscle weakness in some cancer patients.

Increased MYBL2 expression in aggressive hormone-sensitive prostate cancer.

Loss of the histone demethylase KDM5D (lysine-specific demethylase 5D) leads to in vitro resistance of prostate cancer cells to androgen deprivation therapy (ADT) with and without docetaxel. We aimed to define downstream drivers of the KDM5D effect. Using chromatin immunoprecipitation sequencing (ChIP-seq) of the LNCaP cell line (androgen-sensitive human prostate adenocarcinoma) with and without silenced KDM5D, MYBL2-binding sites were analyzed. Associations between MYBL2 mRNA expression and clinical outcomes were assessed in cohorts of men with localized and metastatic hormone-sensitive prostate cancer. In vitro assays with silencing and overexpression of MYBL2 and KDM5D in androgen receptor (AR)-positive hormone-sensitive prostate cancer cell lines, LNCaP and LAPC4, were used to assess their influence on cellular proliferation, apoptosis, and cell cycle distribution, as well as sensitivity to androgen deprivation, docetaxel, and cabazitaxel. We found that silencing KDM5D increased histone H3 lysine K4 (H3K4) trimethylation and increased MYBL2 expression. KDM5D and MYBL2 were negatively correlated with some but not all clinical samples. Higher MYBL2 expression was associated with a higher rate of relapse in localized disease and poorer overall survival in men with metastatic disease in the CHAARTED trial. Lower MYBL2 levels enhanced LNCaP and LAPC4 sensitivity to androgen deprivation and taxanes. In vitro, modifications of KDM5D and MYBL2 altered cell cycle distribution and apoptosis in a cell line-specific manner. These results show that the transcription factor MYBL2 impacts in vitro hormone-sensitive prostate cancer sensitivity to androgen deprivation and taxanes, and lower levels are associated with better clinical outcomes in men with hormone-sensitive prostate cancer.

Bariatric surgery practice patterns among pediatric surgeons in the United States.

BACKGROUND: Metabolic and bariatric surgery (MBS) in adolescents has been shown to be safe and effective, but current practice patterns are variable and poorly understood. The aim of this study is to assess current MBS practice patterns among pediatric surgeons in the United States. METHODS: American Pediatric Surgical Association members were surveyed on current bariatric surgery practices. RESULTS: Four hundred and three (40%) surgeons out of a total of 1013 pediatric surgeons responded to the survey. Only 2 respondents had additional training in MBS (0.5%). One hundred thirty-two (32.6%) report that their practice participates in metabolic and bariatric surgery, with 123 (30.4%) having a specific partner specializing in MBS. Most respondents (92%) stated that they believe high volume is associated with better outcomes with regard to MBS. Only 17 (4.2%) surgeons performed a metabolic and bariatric surgery in the last year. All routinely perform sleeve gastrectomy as their primary procedure. Most (82%) perform procedures with an additional surgeon, either another pediatric surgeon (47%) or an adult bariatric surgeon (47%). All pediatric bariatric surgeons responded that they believe high volume led to better outcomes. Adolescent MBS programs most commonly included pediatric nutritionists (94%), pediatric psychologists (94%), clinical nurses (71%), clinical coordinators (59%), pediatric endocrinologists (59%), and exercise physiologists (52%). CONCLUSION: Only 17 (4.2%) respondents had performed a metabolic and bariatric surgery in the past year, and few of those had additional training in MBS. Future work is necessary to better understand optimal practice patterns for adolescent metabolic and bariatric surgery. TYPE OF STUDY: Review article. LEVEL OF EVIDENCE: Level III.

The Impact of PIK3R1 Mutations and Insulin-PI3K-Glycolytic Pathway Regulation in Prostate Cancer.

PURPOSE: Oncogenic alterations of the PI3K/AKT pathway occur in >40% of patients with metastatic castration-resistant prostate cancer, predominantly via PTEN loss. The significance of other PI3K pathway components in prostate cancer is largely unknown. EXPERIMENTAL DESIGN: Patients in this study underwent tumor sequencing using the MSK-IMPACT clinical assay to capture single-nucleotide variants, insertions, and deletions; copy-number alterations; and structural rearrangements, or were profiled through The Cancer Genome Atlas. The association between PIK3R1 alteration/expression and survival was evaluated using univariable and multivariable Cox proportional-hazards regression models. We used the siRNA-based knockdown of PIK3R1 for functional studies. FDG-PET/CT examinations were performed with a hybrid positron emission tomography (PET)/CT scanner for some prostate cancer patients in the MSK-IMPACT cohort. RESULTS: Analyzing 1,417 human prostate cancers, we found a significant enrichment of PIK3R1 alterations in metastatic cancers compared with primary cancers. PIK3R1 alterations or reduced mRNA expression tended to be associated with worse clinical outcomes in prostate cancer, particularly in primary disease, as well as in breast, gastric, and several other cancers. In prostate cancer cell lines, PIK3R1 knockdown resulted in increased cell proliferation and AKT activity, including insulin-stimulated AKT activity. In cell lines and organoids, PIK3R1 loss/mutation was associated with increased sensitivity to AKT inhibitors. PIK3R1-altered patient prostate tumors had increased uptake of the glucose analogue 18F-fluorodeoxyglucose in PET imaging, suggesting increased glycolysis. CONCLUSIONS: Our findings describe a novel genomic feature in metastatic prostate cancer and suggest that PIK3R1 alteration may be a key event for insulin-PI3K-glycolytic pathway regulation in prostate cancer.

Prevalence of Upper Gastrointestinal Inflammation in Teens With Obesity Prior to Sleeve Gastrectomy.

INTRODUCTION: Upper gastrointestinal (UGI) pathologies are common in adolescents with obesity. This study aims to determine the prevalence of UGI inflammation on preoperative esophagogastroduodenoscopy (EGD) in adolescents undergoing sleeve gastrectomy (SG) and to assess weight loss outcomes. METHODS: This is a retrospective analysis of pathology reports from EGD biopsies performed prior to SG from September 2017 to August 2020. Percentage weight loss was measured at 3, 6, and 12 mo after surgery. Percent total body weight loss (TBWL) was compared between patients with and without UGI inflammation. RESULTS: Thirty adolescents underwent laparoscopic SG. Mean TBWL was 22% of total body weight 12 mo after surgery. Preoperative EGD identified 9 (30%) patients with esophagitis, 10 (33%) with gastritis, and 9 (30%) with duodenitis. Twenty-one patients (70%) had inflammation of at least one area, 5 (17%) were Helicobacter pylori positive, and 1 (3%) had a gastric ulcer that delayed surgery. Five (17%) patients were taking antacids prior to EGD. Patients with preoperative gastric or duodenal inflammation had significantly less TBWL 12 mo after SG compared to patients without gastric (24.6% versus 16.7%, P = 0.04) or duodenal inflammation (25.7% versus 14.1%, P = 0.02). CONCLUSIONS: There is a high prevalence of UGI inflammation in adolescents undergoing SG. Gastric and duodenal inflammation is associated with less TBWL after SG.

Inclusion and representation in the pediatric surgery workforce: Strategies to mitigate bias in the fellowship application process.

Diverse perspectives are critical components of effective teams in every industry. Underrepresentation of minorities in medicine leads to worse outcomes for minority patients, and efforts to increase diversity in the health care workforce are critical. Presently, about 70% of the pediatric surgery workforce is white, and pediatric surgeons at large do not reflect the racial or ethnic diversity of the populations they serve. Pediatric surgery fellowship training programs are the gateway to the field, and fellow selection processes should be optimized to support diversity and inclusion. The Association of Pediatric Surgery Training Program Directors (APSTPD) Diversity Equity and Inclusion subcommittee compiled best practices for bias mitigation during fellow selection, drawing from published literature and personal experiences in our own programs. A list of concrete recommendations was compiled, which can be implemented in every phase from applicant screening to rank list creation. We present these as a position statement that has been endorsed by the executive committee of the APSTPD. Pediatric surgery fellowship programs can utilize this focused review of best practices to mitigate bias and support diverse applicants.

Wavelength optimization for the laser treatment of port wine stains.

Based on the well-known principle of selective photothermolysis, laser has been a promising way for the treatment of port wine stains (PWSs). The laser wavelengths used for PWS's clinical treatment include but are not limited to pulsed dye laser (PDL) in 585-600 nm, long-pulse 755-nm alexandrite, and 1064-nm Nd:YAG lasers. The objective of this study was to investigate the optimal wavelength for PWS's laser treatment. A two-scale mathematic model was constructed to simultaneously quantify macroscale laser energy attenuation in two-layered bulk skin and microscale local energy absorption on target blood vessels within Krogh unit. The effects of morphological parameters, including epidermal melanin content, epidermal thickness, dermal blood content, blood vessel depth, and diameter on laser energy deposition within target blood vessels, were investigated from the visible to near-infrared bands (500-1100 nm). The energy deposition ratio of target blood vessel to epidermal surface was proposed to determine the optimal laser wavelength for PWS with different skin morphological parameters. The bioheat transfer modeling and animal experiment are also conducted to prove our wavelength optimization. The optimal wavelengths for lightly pigmented skin with small and shallow target blood vessels are 580-610 nm in the visible band. This wavelength coincides with commercially used PDL. The optimal wavelength shifts to 940 nm as the epidermal pigmentation increases or the size and blood vessel depth increases. The optimal wavelength changes to 1005 nm as the epidermal pigmentation or the size and burying depth of target blood vessel further increases. Nine hundred forty nanometers can be selected as a general wavelength in PWS treatment to meet the need in most widely morphological structure. Lasers with wavelengths in the 580-610, 940, and 1005 nm regions are effective for treating PWS because of their high optical selectivity in blood over the epidermis.

Dynamic expression of SNAI2 in prostate cancer predicts tumor progression and drug sensitivity.

Prostate cancer is a highly heterogeneous disease, understanding the crosstalk between complex genomic and epigenomic alterations will aid in developing targeted therapeutics. We demonstrate that, even though snail family transcriptional repressor 2 (SNAI2) is frequently amplified in prostate cancer, it is epigenetically silenced in this disease, with dynamic changes in SNAI2 levels showing distinct clinical relevance. Integrative clinical data from 18 prostate cancer cohorts and experimental evidence showed that gene fusion between transmembrane serine protease 2 (TMPRSS2) and ETS transcription factor ERG (ERG) (TMPRSS2-ERG fusion) is involved in the silencing of SNAI2. We created a silencer score to evaluate epigenetic repression of SNAI2, which can be reversed by treatment with DNA methyltransferase inhibitors and histone deacetylase inhibitors. Silencing of SNAI2 facilitated tumor cell proliferation and luminal differentiation. Furthermore, SNAI2 has a major influence on the tumor microenvironment by reactivating tumor stroma and creating an immunosuppressive microenvironment in prostate cancer. Importantly, SNAI2 expression levels in part determine sensitivity to the cancer drugs dasatinib and panobinostat. For the first time, we defined the distinct clinical relevance of SNAI2 expression at different disease stages. We elucidated how epigenetic silencing of SNAI2 controls the dynamic changes of SNAI2 expression that are essential for tumor initiation and progression and discovered that restoring SNAI2 expression by treatment with panobinostat enhances dasatinib sensitivity, indicating a new therapeutic strategy for prostate cancer.

Prognostic and therapeutic significance of COP9 signalosome subunit CSN5 in prostate cancer.

Chromosome 8q gain is associated with poor clinical outcomes in prostate cancer, but the underlying biological mechanisms remain to be clarified. CSN5, a putative androgen receptor (AR) partner that is located on chromosome 8q, is the key subunit of the COP9 signalosome, which deactivates ubiquitin ligases. Deregulation of CSN5 could affect diverse cellular functions that contribute to tumor development, but there has been no comprehensive study of its function in prostate cancer. The clinical significance of CSN5 amplification/overexpression was evaluated in 16 prostate cancer clinical cohorts. Its oncogenic activity was assessed by genetic and pharmacologic perturbations of CSN5 activity in prostate cancer cell lines. The molecular mechanisms of CSN5 function were assessed, as was the efficacy of the CSN5 inhibitor CSN5i-3 in vitro and in vivo. Finally, the transcription cofactor activity of CSN5 in prostate cancer cells was determined. The prognostic significance of CSN5 amplification and overexpression in prostate cancer was independent of MYC amplification. Inhibition of CSN5 inhibited its oncogenic function by targeting AR signaling, DNA repair, multiple oncogenic pathways, and spliceosome regulation. Furthermore, inhibition of CSN5 repressed metabolic pathways, including oxidative phosphorylation and glycolysis in AR-negative prostate cancer cells. Targeting CSN5 with CSN5i-3 showed potent antitumor activity in vitro and in vivo. Importantly, CSN5i-3 synergizes with PARP inhibitors to inhibit prostate cancer cell growth. CSN5 functions as a transcription cofactor to cooperate with multiple transcription factors in prostate cancer. Inhibiting CSN5 strongly attenuates prostate cancer progression and could enhance PARP inhibition efficacy in the treatment of prostate cancer.

Attenuation of SRC Kinase Activity Augments PARP Inhibitor-mediated Synthetic Lethality in BRCA2-altered Prostate Tumors.

PURPOSE: Alterations in DNA damage repair (DDR) pathway genes occur in 20%-25% of men with metastatic castration-resistant prostate cancer (mCRPC). Although PARP inhibitors (PARPis) have been shown to benefit men with mCRPC harboring DDR defects due to mutations in BRCA1/2 and ATM, additional treatments are necessary because the effects are not durable. EXPERIMENTAL DESIGN: We performed transcriptomic analysis of publicly available mCRPC cases, comparing BRCA2 null with BRCA2 wild-type. We generated BRCA2-null prostate cancer cells using CRISPR/Cas9 and treated these cells with PARPis and SRC inhibitors. We also assessed the antiproliferative effects of combination treatment in 3D prostate cancer organoids. RESULTS: We observed significant enrichment of the SRC signaling pathway in BRCA2-altered mCRPC. BRCA2-null prostate cancer cell lines had increased SRC phosphorylation and higher sensitivity to SRC inhibitors (e.g., dasatinib, bosutinib, and saracatinib) relative to wild-type cells. Combination treatment with PARPis and SRC inhibitors was antiproliferative and had a synergistic effect in BRCA2-null prostate cancer cells, mCRPC organoids, and Trp53/Rb1-null prostate cancer cells. Inhibition of SRC signaling by dasatinib augmented DNA damage in BRCA2-null prostate cancer cells. Moreover, SRC knockdown increased PARPi sensitivity in BRCA2-null prostate cancer cells. CONCLUSIONS: This work suggests that SRC activation may be a potential mechanism of PARPi resistance and that treatment with SRC inhibitors may overcome this resistance. Our preclinical study demonstrates that combining PARPis and SRC inhibitors may be a promising therapeutic strategy for patients with BRCA2-null mCRPC.

Pediatric Spontaneous Pneumothorax: Does Initial Treatment Affect Outcomes?

BACKGROUND: Primary spontaneous pneumothorax (PSP) commonly occurs in adolescents, most commonly in males, and has recurrence rates between 20% and 60%. Surgical therapy has long been debated regarding its role in preventing recurrence, with no current consensus on guidelines for care. The purpose of this study is to examine the effect of treatment type on recurrence rates in pediatric PSP. METHODS: This is a single-institution, institutional review board-approved retrospective analysis of patients aged 1 to 18 diagnosed with their first occurrence of PSP between 2009 and 2017. Patient demographics, hospital course, and outcomes over a 2-y period were collected. Patients were divided into nonoperative (oxygen therapy only) management, chest tube placement, and surgical management. The primary outcome was the recurrence rate. RESULTS: Sixty-four patients diagnosed with PSP met inclusive criteria. The mean age was 15.5, and 48 (75%) of patients were men. Twenty-one patients (33%) underwent nonoperative treatment, 24 patients (37.5%) underwent operative treatment with video-assisted thoracoscopic surgery or open thoracotomy, and 19 patients (30%) underwent chest tube or pigtail placement alone. Fifteen patients (23.4%) experienced a recurrence within 2 y: 6 patients (29%) from the nonoperative treatment group, 4 (21%) who were treated with the chest tube only, and 5 (21%) who underwent video-assisted thoracoscopic surgery or open thoracotomy. No statistically significant difference in recurrence rates was found between treatment groups. Pneumothorax size was found to differ between treatment type; larger pneumothoraces were more likely to undergo surgical intervention (P = 0.0003). Smaller pneumothoraces were associated with higher rates of recurrence on multivariate logistic regression analysis (P = 0.046). CONCLUSIONS: Recurrence of PSP in adolescents was found to be 23.4% after 2-y follow-up. Smaller-sized pneumothoraces were associated with higher rates of recurrence, but treatment type did not significantly affect recurrence rates.

Ribonucleotide reductase small subunit M2 is a master driver of aggressive prostate cancer.

Although there are molecularly distinct subtypes of prostate cancer, no molecular classification system is used clinically. The ribonucleotide reductase small subunit M2 (RRM2) gene plays an oncogenic role in many cancers. Our previous study elucidated comprehensive molecular mechanisms of RRM2 in prostate cancer (PC). Given the potent functions of RRM2, we set out to determine whether the RRM2 signature can be used to identify aggressive subtypes of PC. We applied gene ontology and pathway analysis in RNA-seq datasets from PC cells overexpressing RRM2. We refined the RRM2 signature by integrating it with two molecular classification systems (PCS and PAM50 subtypes) that define aggressive PC subtypes (PCS1 and luminal B) and correlated signatures with clinical outcomes in six published cohorts comprising 4000 cases of PC. Increased expression of genes in the RRM2 signature was significantly correlated with recurrence, high Gleason score, and lethality of PC. Patients with high RRM2 levels showed higher PCS1 score, suggesting the aggressive PC feature. Consistently, RRM2-regulated genes were highly enriched in the PCS1 signature from multiple PC cohorts. A simplified RRM2 signature (12 genes) was identified by intersecting the RRM2 signature, PCS1 signature, and the PAM50 classifier. Intriguingly, inhibition of RRM2 specifically targets PCS1 and luminal B genes. Furthermore, 11 genes in the RRM2 signature were correlated with enzalutamide resistance by using a single-cell RNA-seq dataset from PC circulating tumor cells. Finally, high expression of RRM2 was associated with an immunosuppressive tumor-immune microenvironment in both primary prostate cancer and metastatic prostate cancer using CIBERSORT analysis and LM22, a validated leukocyte gene signature matrix. These data demonstrate that RRM2 is a driver of aggressive prostate cancer subtypes and contributes to immune escape, suggesting that RRM2 inhibition may be of clinical benefit for patients with PC.

Experimental investigations on thermal effects of a long-pulse alexandrite laser on blood vessels and its comparison with pulsed dye and Nd:YAG lasers.

Laser has been widely used in the treatment of vascular skin diseases, such as port wine stain, due to the effect of selective photothermolysis in laser on biological tissue. The 755 nm alexandrite laser was expected to achieve better curative effect than the commonly used 585 or 595 nm pulsed dye laser (PDL) because of its deeper tissue penetration. In this study, the dorsal chamber model and microscopic visualization system were used to observe morphology changes on 42 blood vessels before and after irradiation with the 755 nm laser. Results showed that thermal effects of blood vessels intensified with the increase in energy, and high energy was required to produce the same thermal effect as the extension of pulse width. Different from 595 and 1064 nm lasers, partial vessel contraction was dominant thermal effect caused by the 755 nm laser. The bleeding injury rate and thermal effect of the 755 nm laser were between those of 595 nm PDL and 1064 nm Nd:YAG laser. The simulation results proved that 595 nm PDLs were effective for small and shallow target blood vessels. The 755 nm alexandrite lasers were effective in the treatment of hypertrophic and resistant blood vessels to PDL in the skin with low or moderate melanin concentration. The 1064 nm Nd:YAG laser was effective in the treatment of deeply buried and enlarged target blood vessels in the skin with high melanin concentration. The simulation results were supported by published clinical observations.

Significance of BRCA2 and RB1 Co-loss in Aggressive Prostate Cancer Progression.

PURPOSE: Previous sequencing studies revealed that alterations of genes associated with DNA damage response (DDR) are enriched in men with metastatic castration-resistant prostate cancer (mCRPC). BRCA2, a DDR and cancer susceptibility gene, is frequently deleted (homozygous and heterozygous) in men with aggressive prostate cancer. Here we show that patients with prostate cancer who have lost a copy of BRCA2 frequently lose a copy of tumor suppressor gene RB1; importantly, for the first time, we demonstrate that co-loss of both genes in early prostate cancer is sufficient to induce a distinct biology that is likely associated with worse prognosis. EXPERIMENTAL DESIGN: We prospectively investigated underlying molecular mechanisms and genomic consequences of co-loss of BRCA2 and RB1 in prostate cancer. We used CRISPR-Cas9 and RNAi-based methods to eliminate these two genes in prostate cancer cell lines and subjected them to in vitro studies and transcriptomic analyses. We developed a 3-color FISH assay to detect genomic deletions of BRCA2 and RB1 in prostate cancer cells and patient-derived mCRPC organoids. RESULTS: In human prostate cancer cell lines (LNCaP and LAPC4), loss of BRCA2 leads to the castration-resistant phenotype. Co-loss of BRCA2-RB1 in human prostate cancer cells induces an epithelial-to-mesenchymal transition, which is associated with invasiveness and a more aggressive disease phenotype. Importantly, PARP inhibitors attenuate cell growth in human mCRPC-derived organoids and human CRPC cells harboring single-copy loss of both genes. CONCLUSIONS: Our findings suggest that early identification of this aggressive form of prostate cancer offers potential for improved outcomes with early introduction of PARP inhibitor-based therapy.See related commentary by Mandigo and Knudsen, p. 1784.

The influence of morphological distribution of melanin on parameter selection in laser thermotherapy for vascular skin diseases.

Port wine stains (PWSs) are congenital vascular malformations that progressively darken and thicken with age. Currently, laser therapy is the most effective way in clinical management of PWS. It is known that skin pigmentation (melanin content) affects the radiant exposure that can be safely applied to treat PWS. However, the effect of melanin distribution in the epidermis on the maximum safe radiant exposure has not been studied previously. In this study, 10 different morphological distributions of melanin were proposed according to the formation and migration characteristics of melanin, and the two-scale heat transfer model was employed to investigate the influence of melanin distribution on the threshold radiant exposure of epidermis and blood vessels. The results show that melanin distributions do have a strong effect on laser parameter selection. When uniform melanin distribution is assumed, the threshold radiant exposure to damage a typical PWS blood vessel (50 µm diameter) is 8.62 J/cm2 lower than that to injure epidermis. The optimal pulse duration is 1-5 ms for a typical PWS blood vessel of 50 µm when melanin distribution is taken into consideration. PWS blood vessels covered by non-uniformly distributed melanin are more likely to have poor response to laser treatment.

[Application of totally extraperitoneal renal autotransplantation with Boari flap-pelvis anastomosis in upper urinary tract urothelial carcinomas treatment].

OBJECTIVE: To evaluate the feasibility and effectiveness of the totally extraperitoneal renal autotransplantation with boari flap-pelvis anastomosis in the treatment of upper urinary tract urothelial carcinoma (UTUC), and to review the experience of renal autotransplantation for UTUC treatment. METHODS: One case of applying the totally extraperitoneal renal autotransplantation with boari flap-pelvis anastomosis to the UTUC treatment was reported, and related literature was reviewed. The patient was a sixty-four-year old man who received right radical nephroureterectomy for right ureteral carcinoma 1 year before and diagnosed as left ureteral carcinoma(G2, high grade) this time. In order to preserve his renal function and avoid the shortness of common kidney-sparing surgery, a totally extraperitoneal procedure, including retroperitoneoscopic nephrectomy, ureterectomy, renal autotransplantation and Boari flap-pelvis anastomosis, was performed to the patient. RESULTS: The operation was completed successfully without perioperative complications. The renal function recovered to preoperative level within 1 week. No deterioration of renal function during the follow-up and no tumor recurrence was observed under cystoscopy at the 3-month postoperative consult. CONCLUSION: The totally extraperitoneal renal autotransplantation with Boari flap-pelvis anastomosis is a feasible and effective treatment for UTUC. The innovative procedure has several advantages compared to the former ones. The extraperitoneal procedure results in significantly less pain, shorter hospital stay, decreased overall time to recovery and lower bowel complications risk without warm ischemia time extension. Meanwhile, the Boari flap-pelvis anastomosis simplifies the follow -up protocols and creates an easy route for cystoscopy and topical therapy. From the systematic clinical analysis, as well as the related literature review, it's been concluded that the renal autotransplantation can be a reasonable option for the patients who have UTUC in solitary kidney or have bilateral UTUC. This type of treatment possesses advantages of preservation of renal function and total resection of malignant lesions. But long-term data and large cohort study on renal function or tumor recurrence are still absent which will be necessary to confirm the advantages of this approach.

Methylation-associated miR-193b silencing activates master drivers of aggressive prostate cancer.

Epigenetic silencing of miRNA is a primary mechanism of aberrant miRNA expression in cancer, and hypermethylation of miRNA promoters has been reported to contribute to prostate cancer initiation and progression. Recent data have shown that the miR-193b promoter is hypermethylated in prostate cancer compared with normal tissue, but studies assessing its functional significance have not been performed. We aimed to elucidate the function of miR-193b and identify its critical targets in prostate cancer. We observed an inverse correlation between miR-193b level and methylation of its promoter in The Cancer Genome Atlas (TCGA) cohort. Overexpression of miR-193b in prostate cancer cell lines inhibited invasion and induced apoptosis. We found that a majority of the top 150 genes downregulated when miR-193b was overexpressed in liposarcoma are overexpressed in metastatic prostate cancer and that 41 miR-193b target genes overlapped with the 86 genes in the aggressive prostate cancer subtype 1 (PCS1) signature. Overexpression of miR-193b led to the inhibition of the majority of the 41 genes in prostate cancer cell lines. High expression of the 41 genes was correlated with recurrence of prostate cancer. Knockdown of miR-193b targets FOXM1 and RRM2 in prostate cancer cells phenocopied overexpression of miR-193b. Dual treatment with DNA methyltransferase (DNMT) and histone deacetylase (HDAC) inhibitors decreased miR-193b promoter methylation and restored inhibition of FOXM1 and RRM2. Our data suggest that silencing of miR-193b through promoter methylation may release the inhibition of PCS1 genes, contributing to prostate cancer progression and suggesting a possible therapeutic strategy for aggressive prostate cancer.

Long noncoding RNA LINC00473 indicates a poor prognosis of breast cancer and accelerates tumor carcinogenesis by competing endogenous sponging miR-497.

OBJECTIVE: Long noncoding RNA LINC00473 (LINC00473) has been reported to be involved in the progression of several tumors. Our present study was conducted to study the potential roles and mechanism of long noncoding RNA LINC00473 (LINC00473) on cells proliferation, migration, invasion, and apoptosis of breast cancer (BC). PATIENTS AND METHODS: RT-PCR was applied for the analysis of LINC00473 in BC cell lines and tissues samples. The correlations between the LINC00473 levels and clinicopathological parameters were investigated. Kaplan-Meier methods and Cox proportional hazards regression models were explored to reveal potential associations of LINC00473 levels with overall survival of BC patients. The effect of LINC00473 on tumor behavior was evaluated by colony formation, Cell Counting Kit-8, EdU assays, flow-cytometric analysis, wound healing assays and transwell assays. Interactions between LINC00473 and miR-497 were determined using a luciferase reporter assay and RT-PCR assays. RESULTS: Upregulation of the expression of LINC00473 was found in BC samples and cell lines, in comparison with non-tumor breast tissues and human breast epithelial cells. High expression of LINC00473 was correlated with lymph node metastasis, clinical stage, and poorer outcome in BC patients. Multivariate logistic regression assays further showed LINC00473 as an independent prognostic factor in BC. Lost-of-function assays revealed that knockdown of LINC00473 resulted in the suppression of tumor cell proliferation, promotion of cells apoptosis, inhibition of cells metastasis. Bioinformatics analysis and luciferase reporter assays revealed LINC00473 bonds to miR-497. Further RT-PCR revealed that knockdown of LINC00473 suppressed the expressions of miR-497 in BC cells. CONCLUSIONS: Our data revealed that LINC00473 acted as a tumor promoter in BC and LINC00473/miR-497 axis may be a novel therapeutic strategy for this tumor.