Depletion of Neural Crest-Derived Cells Leads to Plasma Noradrenaline Decrease and Alters T Cell Development.

The differentiation of neural crest (NC) cells into various cell lineages contributes to the formation of many organs, including the thymus. In this study, we explored the role of NC cells in thymic T cell development. In double-transgenic mice expressing NC-specific Cre and the Cre-driven diphtheria toxin receptor, plasma noradrenaline and adrenaline levels were significantly reduced, as were thymic T cell progenitors, when NC-derived cells were ablated with short-term administration of diphtheria toxin. Additionally, yellow fluorescent protein+ NC-derived mesenchymal cells, perivascular cells, and tyrosine hydroxylase+ sympathetic nerves in the thymus significantly decreased. Furthermore, i.p. administration of 6-hydroxydopamine, a known neurotoxin for noradrenergic neurons, resulted in a significant decrease in thymic tyrosine hydroxylase+ nerves, a phenotype similar to that of depleted NC-derived cells, whereas administration of a noradrenaline precursor for ablating NC-derived cells or sympathetic nerves rarely rescued this phenotype. To clarify the role of NC-derived cells in the adult thymus, we transplanted thymus into the renal capsules of wild-type mice and observed abnormal T cell development in lethally irradiated thymus with ablation of NC-derived cells or sympathetic nerves, suggesting that NC-derived cells inside and outside of the thymus contribute to T cell development. In particular, the ablation of NC-derived mesenchymal cells in the thymus decreases the number of thymocytes and T cell progenitors. Overall, ablation of NC-derived cells, including sympathetic nerves, in the thymus leads to abnormal T cell development in part by lowering plasma noradrenalin levels. This study reveals that NC-derived cells including mesenchymal cells and sympathetic nerves within thymus regulate T cell development.

Fibroblast-derived exosomal microRNA regulates NKX3-1 expression in androgen-sensitive, androgen receptor-dependent prostate cancer cells.

Androgen deprivation therapy (ADT) targeting androgen production and androgen receptor (AR) signaling is the primary antihormonal therapy in the treatment of advanced prostate cancer (PCa). However, no clinically established molecular biomarkers have been identified to predict the effectiveness of ADT before starting ADT. The tumor microenvironment of PCa contains fibroblasts that regulate PCa progression by producing multiple soluble factors. We have previously reported that AR-activating factor-secreted fibroblasts increase the responsiveness of androgen-sensitive, AR-dependent PCa cells to ADT. Thus, we hypothesized that fibroblast-derived soluble factors may affect cancer cell differentiation by regulating cancer-related gene expression in PCa cells and that the biochemical characteristics of fibroblasts may be used to predict the effectiveness of ADT. Here, we investigated the effects of normal fibroblasts (PrSC cells) and three PCa patient-derived fibroblast lines (pcPrF-M5, -M28, and -M31 cells) on the expression of cancer-related genes in androgen-sensitive, AR-dependent human PCa cells (LNCaP cells) and three sublines showing different androgen sensitivities and AR dependencies. The mRNA expression of the tumor suppressor gene NKX3-1 in LNCaP cells and E9 cells (which show low androgen sensitivity and AR dependency) was significantly increased by treatment with conditioned media from PrSC and pcPrF-M5 cells but not from pcPrF-M28 and pcPrF-M31 cells. Notably, no upregulation of NKX3-1 was observed in F10 cells (AR-V7-expressing, AR-independent cells with low androgen sensitivity) and AIDL cells (androgen-insensitive, AR-independent cells). Among 81 common fibroblast-derived exosomal microRNAs that showed 0.5-fold lower expression in pcPrF-M28 and pcPrF-M31 cells than in PrSC and pcPrF-M5 cells, miR-449c-3p and miR-3121-3p were found to target NKX3-1. In only LNCaP cells, the NKX3-1 mRNA expression was significantly increased by transfection of an miR-3121-3p mimic but not that of the miR-449c-3p mimic. Thus, fibroblast-derived exosomal miR-3121-3p may be involved in preventing the oncogenic dedifferentiation of PCa cells by targeting NKX3-1 in androgen-sensitive, AR-dependent PCa cells.

[A Case of Combined Use of Endoscopic Submucosal Dissection and Transanal Excision for Early Rectal Cancer with Extension into the Anal Canal].

A 77-year-old woman visited our hospital after noticing bleeding during defecation. Lower gastrointestinal endoscopy revealed an early rectal tumor with extension into the anal canal, thus transanal excision was performed. However, histopathological examination revealed a positive surgical margin, therefore, additional transanal excision was performed with endoscopic submucosal dissection, and the residual cancer tissue was completely resected. At one year after surgery, no recurrence has been observed.

[A Case of Complete Onychomadesis after Oral UFT/LV Therapy with Long-Term Follow-Up].

A 79-year-old man underwent a radical resection for cecal cancer. The pathological diagnosis was pT4a, N1a, M0, pStage Ⅲb(Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma, 9th edition). He was treated with oral UFT/LV as adjuvant chemotherapy for 6 months. At 7 months, after the end of treatment, he lost all the nail plates on his fingers and toes. A dermatologist examined him and diagnosed these as side effects of the anticancer drugs. Due to this issue, he was unable to perform routine, fine work using his fingertips. Approximately 1 year and 5 months after the completion of treatment, his nail plates regenerated to the extent that about half of his nail beds were covered. At 2 years after the completion of treatment, the nail plates began to cover the entire nail beds. Although there have been very few reports of onychomadesis as a delayed adverse event of anticancer drugs, oncologists must be aware of this possibility, as onychomadesis may impact patients' quality of life significantly.

[Decision-Making Regarding Adjuvant Therapy for Hormone Receptor-Positive, HER2-Negative Early Breast Cancer].

In December 2021, abemaciclib was approved as an adjuvant treatment for hormone receptor-positive, HER2-negative, high-risk early breast cancer in Japan. The Oncotype DX Breast Cancer Recurrence Score program(Oncotype DX)is a test that can be used to limit overtreatment in hormone receptor-positive, HER2-negative, low-risk early breast cancer. Although the target groups of both these are different and usually without many overlapping indications, we encountered a case in which this therapy and test were used in a short time period. Our experience suggests that even if the result of Oncotype DX indicates that hormone therapy alone is sufficient, it does not imply that abemaciclib is unnecessary, although this has not been directly studied in the monarchE trial. While a wider choice of treatment options is desirable for patients, more clinical data and trials are needed to further validate the utility of abemaciclib without chemotherapy.

Principles of plastid reductive evolution illuminated by nonphotosynthetic chrysophytes.

The division of life into producers and consumers is blurred by evolution. For example, eukaryotic phototrophs can lose the capacity to photosynthesize, although they may retain vestigial plastids that perform other essential cellular functions. Chrysophyte algae have undergone a particularly large number of photosynthesis losses. Here, we present a plastid genome sequence from a nonphotosynthetic chrysophyte, "Spumella" sp. NIES-1846, and show that it has retained a nearly identical set of plastid-encoded functions as apicomplexan parasites. Our transcriptomic analysis of 12 different photosynthetic and nonphotosynthetic chrysophyte lineages reveals remarkable convergence in the functions of these nonphotosynthetic plastids, along with informative lineage-specific retentions and losses. At one extreme, Cornospumella fuschlensis retains many photosynthesis-associated proteins, although it appears to have lost the reductive pentose phosphate pathway and most plastid amino acid metabolism pathways. At the other extreme, Paraphysomonas lacks plastid-targeted proteins associated with gene expression and all metabolic pathways that require plastid-encoded partners, indicating a complete loss of plastid DNA in this genus. Intriguingly, some of the nucleus-encoded proteins that once functioned in the expression of the Paraphysomonas plastid genome have been retained. These proteins were likely to have been dual targeted to the plastid and mitochondria of the chrysophyte ancestor, and are uniquely targeted to the mitochondria in Paraphysomonas Our comparative analyses provide insights into the process of functional reduction in nonphotosynthetic plastids.

[Hyponatremia Causing a Tonic-Clonic Seizure after Breast Cancer Surgery-The Medical Safety Perspective].

A 61-year-old woman was found to have calcifications in the CD region of the left breast. She had previously undergone total hysterectomy and bilateral oophorectomy for endometriosis at the age of 37 years. Since age 59 years, she had been attending an otorhinolaryngology clinic because of vertigo. Blood tests showed no abnormal findings. Left breast cancer (cT1N0M0, stage Ⅰ)was diagnosed, and left mastectomy and sentinel lymph node biopsy were performed. She developed postoperative nausea, and at 37 hours postoperatively, she was unable to communicate and exhibited suspected delirium. At 43 hours postoperatively a tonic-clonic seizure occurred. Hyponatremia, with serum sodium of 114 mEq/L, was present. Sodium supplementation was provided, and the patient became capable of communication 8 hours after seizure onset(Na 121 mEq/L). A hyponatremic tonic-clonic seizure is extremely rare after breast cancer surgery, and the abnormal behavior of the present patient 31 hours after surgery was also highly unusual. With such an unusual presentation, the possibility that something specific is happening must be considered. This case gave us the opportunity to review patient management after breast cancer surgery, emergency response and preparations, and nursing education from the medical safety perspective.

Heterogeneous induction of an invasive phenotype in prostate cancer cells by coculturing with patient-derived fibroblasts.

Prostate cancer (PCa) cells frequently invade the surrounding stroma, leading to heterogeneous formation of structural atypia. The surrounding stroma contains multiple functionally diverse populations of fibroblasts that trigger numerous changes in PCa cells including motility. Thus, we hypothesized that direct or indirect contact of PCa cells with fibroblasts determines an invasive phenotype in PCa cells. We investigated the effects of 10 different patient-derived fibroblast lines on the three-dimensional (3D) morphogenesis of PCa cells growing on a viscous substrate in vitro. When grown alone, all 10 patient-derived fibroblast lines clumped on the viscous substrate, whereas the human androgen-sensitive PCa cell line LNCaP did not. Cocultures of LNCaP cells with seven of the patient-derived fibroblast lines (PrSC, pcPrF-M5, pcPrF-M7, pcPrF-M23, pcPrF-M24, pcPrF-M28, and pcPrF-M31) formed a thick fibroblast layer that resembled human prostate stromal structures. In contrast, cocultures of LNCaP cells with the remaining three fibroblast lines (NPF-M13, pcPrF-M10, and pcPrF-M26) did not form a thick fibroblast layer. Of the seven fibroblast lines that caused thick layer formation, four patient-derived fibroblast lines (PrSC, pcPrF-M5, pcPrF-M28, and pcPrF-M31) induced an invasive phenotype in LNCaP cells with a cord-like infiltrating growth pattern, whereas the other three fibroblast lines (pcPrF-M7, pcPrF-M23, and pcPrF-M24) induced no or a very weak invasive phenotype. Using cell culture inserts, none of the four patient-derived fibroblast lines that induced an invasive phenotype (PrSC, pcPrF-M5, pcPrF-M28, and pcPrF-M31) affected CDH1 mRNA expression in LNCaP cells; yet, two patient-derived fibroblast lines (pcPrF-M5 and pcPrF-M28) increased CDH2 mRNA expression in LNCaP cells, whereas the other two fibroblast lines (PrSC and pcPrF-M31) did not. These results suggest that the existence of multiple functionally diverse populations of fibroblasts in PCa tissue may be responsible for the diversity in PCa cell invasion, leading to heterogeneous formation of structural atypia.

TDP2 suppresses genomic instability induced by androgens in the epithelial cells of prostate glands.

Androgens stimulate the proliferation of epithelial cells in the prostate by activating topoisomerase 2 (TOP2) and regulating the transcription of target genes. TOP2 resolves the entanglement of genomic DNA by transiently generating double-strand breaks (DSBs), where TOP2 homodimers covalently bind to 5' DSB ends, called TOP2-DNA cleavage complexes (TOP2ccs). When TOP2 fails to rejoin TOP2ccs generating stalled TOP2ccs, tyrosyl DNA phosphodiesterase-2 (TDP2) removes 5' TOP2 adducts from stalled TOP2ccs prior to the ligation of the DSBs by nonhomologous end joining (NHEJ), the dominant DSB repair pathway in G0 /G1 phases. We previously showed that estrogens frequently generate stalled TOP2ccs in G0 /G1 phases. Here, we show that physiological concentrations of androgens induce several DSBs in individual human prostate cancer cells during G1 phase, and loss of TDP2 causes a five times higher number of androgen-induced chromosome breaks in mitotic chromosome spreads. Intraperitoneally injected androgens induce several DSBs in individual epithelial cells of the prostate in TDP2-deficient mice, even at 20 hr postinjection. In conclusion, physiological concentrations of androgens have very strong genotoxicity, most likely by generating stalled TOP2ccs.

Examination of the efficacy of olanexidine gluconate for surgical site infections in colorectal cancer elective surgery.

INTRODUCTION: The preoperative skin antiseptic, olanexidine gluconate (OLG), which has been available in Japan since 2015, is also known to be effective against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and Pseudomonas aeruginosa. This study attempted to clarify OLG efficacy against surgical site infections and antiseptic-related adverse events as compared to conventionally used povidone iodine (PVP-I). METHODS: Propensity score matching was performed on 307 patients who underwent surgery for colorectal tumors at our hospital. All 116 cases (58 PVP-I cases, 58 OLG cases) who were diagnosed with colorectal cancer were included. We examined surgical site infection rate after disinfection using PVP-I and OLG, length of hospitalization stay (days) after surgery, adverse events associated with antiseptics, and additional medical costs associated with adverse events caused by antiseptics. RESULTS: The surgical site infection rate was 8.6% in both the PVP-I and OLG groups, with no significant difference observed. The number of postoperative hospitalization days in the PVP-I group was 12.9 (±6.9) days and 16.4 (±14.6) days in the OLG group, which exhibited no significant difference (p = 0.10). Although no complications due to antiseptics were observed in the PVP-I group, skin-related side effects were observed in 8 patients (13.8%) in the OLG group. The median additional medical cost was 730 [120-1823] yen. CONCLUSIONS: OLG was as effective as the conventional PVP-I for surgical site infections during colorectal cancer elective surgery. However, significantly higher skin disorders occurred in OLG, thereby making it necessary to evaluate antiseptic use in conjunction with patient burden.

[A Case of Low-Grade Appendiceal Mucinous Neoplasm for Which Laparoscopic Surgery Was Effective].

Abdominal ultrasonography during a regular medical examination showed that a 70-year-old man had an approximately 10 cm cystic tumor in the lower abdomen. Abdominal computed tomography showed that the appendix had swollen to a size of 130 mm×44 mm. As no other tests suggested malignancy, the patient's condition was diagnosed as a low-grade appendiceal mucinous tumor and he underwent laparoscopic ileocecal resection and lymph node D2 dissection. Laparoscopic surgery was completed without damaging the tumor. There has been no recurrence after the operation for 2 years now.

Castration-induced stromal remodeling disrupts the reconstituted prostate epithelial structure.

The normal prostate epithelial structure is maintained by homeostatic interactions with smooth muscle cells. However, structural alterations of the stroma are commonly observed in prostatic proliferative diseases, leading to the abnormalities of prostate epithelial structure. A decrease in the androgen level experimentally induces stromal remodeling, i.e., replacement of smooth muscle cells with fibroblasts or myofibroblasts. In this study, we investigated the effects of castration-induced stromal remodeling and subsequent aberrant activation of epithelial-stromal interactions on the reconstituted human prostate-like epithelial structure. We performed in vivo experiments using the human prostate epithelial cell line BPH-1 and fetal rat urogenital sinus mesenchyme to generate heterotypic tissue recombinants that form human prostate-like epithelial structure (i.e., solid- and canalized-epithelial cords). Host mice were castrated at 12 weeks post transplantation (castration) and implanted with a dihydrotestosterone pellet at 14 days post castration (androgen replacement treatment; ART). In the castration group, the percentages of fibrotic area and disrupted prostate epithelial structure without the basement membrane (BM) increased proportionally in a time-dependent manner, but were suppressed by ART. In the castration group, tenascin-C (TNC)-positive fibroblasts were abundant in the stroma surrounding disrupted prostate epithelial structure without the BM. TGF-ß1 secretion from BPH-1 cells was increased by co-culturing with human primary cultured prostate fibroblasts. TNC mRNA expression was increased in fibroblasts co-culturing with BPH-1 cells and was suppressed by treatment with a TGF-ß RI kinase inhibitor. Moreover, in the castration group, the percentage of p-Smad2-positive cells was significantly higher in the stroma surrounding disrupted prostate epithelial structure without the BM. Our results demonstrate that castration-induced stromal remodeling disrupted the reconstituted human prostate-like epithelial structure and induced the appearance of TNC-positive fibroblasts accompanied by activation of TGF-ß signaling. The alteration of prostate stromal structure may be responsible for loss of the BM and epithelial cell polarity.

SOX11-induced decrease in vimentin and an increase in prostate cancer cell migration attributed to cofilin activity.

SOX11 is a transcription factor in the SOX family of genes that regulate multiple cellular events by influencing the expression of key genes in developmental, physiological, and tumorigenic cells. To elucidate the role of SOX11 in prostate cancer cells, PC-3 prostate cancer cells were cloned (S6 and S9 cells) to highly express SOX11. We demonstrated that both S6 and S9 lose vimentin expression, acquiring epithelial marker proteins, which indicates the Epithelial state phenotype. S6 and S9 cells have cancer-promoting characteristics that include higher migratory properties compared with control cells. The mechanisms that are responsible for the enhanced migration are cofilin activity and keratin 18 expression. TCGA (The Cancer Genome Atlas) dataset analysis revealed that metastatic prostate cancer tumors tend to have more SOX11 gene amplification compared with primary tumors. These results suggest the tumor promotive role and epithelial protein induction of SOX11 in prostate cancer cell.

[Treatment Regimens for Breast Cancer in Elderly Patients in Whom the Diagnosis Was Switched from Malignant Phyllodes Tumor to Spindle-Cell Carcinoma after Surgery].

The patient was a 79-year-old woman with a left breast mass. Magnetic resonance imaging showed a cystic mass with a diameter of 10×8 cm and an ulcer in the upper outer quadrant and the nipple-areola region of the left breast. Intracystic carcinoma was thus suspected. A mass with a diameter of 1 cm was found in the upper outer quadrant of the right breast. Needle biopsy revealed that a cystic mass in the left breast was diagnosed as a malignant phyllodes tumor. A mass in the right breast was diagnosed as Luminal A breast cancer. The clinical tumor stage was T1N0M0. Computed tomography showed no enlarged bilateral axillary lymph nodes. In the left breast, mastectomy was performed with extensive skin excision above the tumor. In the right breast, partial mastectomy was performed with sentinel lymph node biopsy. On postoperative pathological examination, the diagnosis of left breast tumor was triple-negative spindle-cell carcinoma. The pathological tumor stage was diagnosed as T4bNxM0. Taking into consideration treatment according to breast cancer stage and age, we selected 4 courses of weekly-paclitaxel, endocrine therapy, irradiation to the left chest wall, and irradiation to the residual right breast. The preoperative diagnosis was malignant phyllodes tumor. The postoperative diagnosis was switched from malignant phyllodes tumor to spindle-cell carcinoma. It was therefore difficult to determine the presence or absence of additional resection and postoperative treatment regimens. Even though the preoperative diagnosis was a malignant phyllodes tumor, surgical procedures such as sentinel lymph-node biopsy should be considered, taking into account the possibility of breast cancer.

[A Case Report of Triple Negative Breast Cancer Diagnosed as Granulomatous Mastitis].

Granulomatous mastitis is a chronic inflammatory disease of unknown causes that forms a breast mass and may be difficult to distinguish from breast cancer on imaging studies. The patient was a woman in her 50's. Needle biopsy was performed for a mass in the upper outer quadrant of the right breast and revealed granulomatous mastitis. Breast magnetic resonance imaging showed that the tumor was malignant. Taking into account that there is a difference between histologic findings and imaging findings and that surgery after steroid therapy for granulomatous mastitis is more likely to cause complications, we decided to perform lumpectomy. The definitive pathological diagnosis was a triple negative, pT1cN0cM0 medullary carcinoma. Postoperative adjuvant chemotherapy was performed. The absence of axillary lymph-node metastasis was confirmed by right axillary sentinel lymph-node biopsy. Radiotherapy was performed on the preserved breast region. Even if granulomatous mastitis is diagnosed, biopsy should be repeated while paying attention to biopsy methods if there is a difference between pathological findings and image findings.

Tyrosine kinase inhibitor therapy prescribed for non-urologic diseases can modify PSA titers in urology patients.

BACKGROUND: The tyrosine kinase inhibitors (TKI), imatinib and nilotinib, are used to treat chronic myelogenous leukemia (CML). In three CML patients being monitored for urologic diseases, we observed that switching of TKI therapy affected prostate-specific antigen (PSA) titers. Urologists and other medical professionals need to be aware of the potential side-effects of drugs that patients may be receiving for other indications to modify this important prostate diseases indicator. TKIs may affect PSA titers independent of prostate growth or volume. MATERIALS AND METHODS: We followed PSA levels in urology patients who were also undergoing TKI treatment for CML. We determined the effects of nilotinib and imatinib on proliferation, AR and PSA expression in the LNCaP and 22Rv1 prostate cancer (PCa) cell lines using real-time PCR and Western blotting. RESULTS: Clinically, nilotinib and dasatinib reversibly reduced PSA titers compared to imatinib. At high doses nilotinib and imatinib both demonstrated antiproliferative effects in the PCa cells. At low doses expression of AR and PSA was decreased by both drugs, at mRNA and protein levels. Nilotinib exerted greater effects at lower doses than imatinib. CONCLUSIONS: Nilotinib down-regulates serum PSA in patients being treated for non-urological indications, potentially masking a clinical useful marker, we cannot exclude a similar but smaller effect of imatinib. Nilotinib and imatinib both decreased AR and PSA expression in PCa cell lines with the nilotinib effect evident at lower doses. Urologists must appreciate the effects of drugs provided for other diseases on PSA titers and be aware that sudden changes may not reflect underlying prostatic disease.

Antifibrotic Agent Pirfenidone Suppresses Proliferation of Human Pancreatic Cancer Cells by Inducing G0/G1 Cell Cycle Arrest.

BACKGROUND: Pirfenidone (PFD), which is an antifibrotic agent used for treatment of idiopathic pulmonary fibrosis, induces G0/G1 cell cycle arrest in fibroblasts. We hypothesized that PFD-induced G0/G1 cell cycle arrest might be achieved in other types of cells, including cancer cells. Here we investigated the effects of PFD on the proliferation of pancreatic cancer cells (PCCs) in vitro. METHOD: Human skin fibroblasts ASF-4-1 cells and human prostate stromal cells (PrSC) were used as fibroblasts. PANC-1, MIA PaCa-2, and BxPC-3 cells were used as human PCCs. Cell cycle and apoptosis were analyzed using flow cytometer. RESULTS: First, we confirmed that PFD suppressed cell proliferation of ASF-4-1 cells and PrSC and induced G0/G1 cell cycle arrest. Under these experimental conditions, PFD also suppressed cell proliferation and induced G0/G1 cell cycle arrest in all PCCs. In PFD-treated PCCs, expression of p21 was increased but that of CDK2 was not clearly decreased. Of note, PFD did not induce significant apoptosis among PCCs. CONCLUSIONS: These results demonstrated that the antifibrotic agent PFD might have antiproliferative effects on PCCs by inducing G0/G1 cell cycle arrest. This suggests that PFD may target not only fibroblasts but also PCCs in the tumor microenvironment of pancreatic cancer.

Interleukin-6 induces VEGF secretion from prostate cancer cells in a manner independent of androgen receptor activation.

BACKGROUND: The reduced androgen-sensitivity of prostate cancer (PCa) cells is an important clinical development because of its association with the cells' progression to castration-resistant prostate cancer (CRPC). During androgen deprivation therapy (ADT), stroma-derived growth factors and cytokines can activate the androgen receptor (AR). For example, IL-6 is a multifunctional cytokine that is involved in the malignancy of PCa cells through AR activation. In the present study, we used an androgen-sensitive human PCa cell line (LNCaP) and its sublines to investigate the relationship between the responsiveness of PCa cells to IL-6 treatment and the cellular AR signaling pathway. METHODS: The androgen-low-sensitive F10 and E9 cells were obtained from LNCaP cells by limiting dilution method in regular culture condition. In contrast, the androgen-insensitive AIDL cells were established from LNCaP cells by continuous passaging in hormone-depleted condition. Original carcinoma-associated fibroblasts (CAFs) PCaSC-8 and PCaSC-9 cells were isolated from needle biopsy samples of PCa patients. RESULTS: In fibroblasts derived from PCa patients, IL-6 secretion was generally higher than that observed with normal fibroblasts. In contrast, IL-6 secretion was not detected in LNCaP and its sublines. The soluble IL-6 receptor was detected in PCa cells but not in fibroblasts. IL-6 treatment suppressed cell growth of LNCaP, F10, and E9 cells but not AIDL cells and it was accompanied with neuroendocrine-like differentiation. Induction of PSA secretion was observed in IL-6-treated LNCaP and F10 cells. VEGF secretion was strongly induced in IL-6-treated LNCaP and AIDL cells. IL-6-induced VEGF secretion was significantly suppressed by a PI3K inhibitor (LY294002) and it was accompanied by inhibited phosphorylation of Akt. CONCLUSIONS: Our results suggest that IL-6 might induce VEGF secretion from PCa cells in a manner independent of AR activation. To prevent IL-6-induced VEGF secretion, inhibition of the PI3K/AKT signaling pathway could be an important pharmacological goal regardless of ADT.

Fibroblasts prolong serum prostate-specific antigen decline after androgen deprivation therapy in prostate cancer.

In patients with prostate cancer (PCa), serum prostate-specific antigen (PSA) is a useful marker for evaluating the effects of androgen deprivation therapy (ADT). Intuitively, most urologists expect that a more rapid PSA decline in response to ADT would be positively associated with extended survival. Recently, we have reported that prolonged gradual serum PSA decline after ADT is strongly associated with favorable prognosis in PCa patients, however, the mechanism remains unknown. We investigated the role of fibroblasts in serum PSA decline after ADT. We performed in vitro experiments using androgen-sensitive, androgen receptor (AR)-positive prostate epithelial cell lines (LNCaP, 22Rv1, and RWPE-1 cells), commercially available prostate stromal cells (PrSC), and primary cultures of prostate fibroblasts (pcPrFs). In LNCaP and 22Rv1 cells, PSA production was increased by co-culture with fibroblasts under androgen-deprived conditions. In an in vivo model using LNCaP cells, serum PSA declined rapidly after ADT becoming undetectable within 14 days in mice inoculated with LNCaP cells alone. In contrast, when LNCaP cells were co-inoculated with fibroblasts, serum PSA levels were still high on 14 days post ADT and did not drop to undetectable levels until 21 days post ADT. Tumor volumes and Ki67 labeling indices were not altered between days 14 and 21 post ADT in mice inoculated with LNCaP cells; however, those in mice inoculated with LNCaP cells plus fibroblasts decreased gradually. PSA protein was detected in all tumors on 21 days post ADT by immunohistochemical staining. Microvessel densities were higher on 14 days post ADT for tumors from mice inoculated with LNCaP cells plus fibroblasts as compared with LNCaP cells alone. In summary, co-inoculation of fibroblasts with LNCaP cells prolonged serum PSA decline after ADT and enhanced the efficacy of ADT. Prolonged serum PSA decline may indicate the presence of protective fibroblasts that preserve the AR dependence of PCa cells, improving treatment efficacy.

Proposal of a Twin Arginine Translocator System-Mediated Constraint against Loss of ATP Synthase Genes from Nonphotosynthetic Plastid Genomes. [Corrected].

Organisms with nonphotosynthetic plastids often retain genomes; their gene contents provide clues as to the functions of these organelles. Yet the functional roles of some retained genes-such as those coding for ATP synthase-remain mysterious. In this study, we report the complete plastid genome and transcriptome data of a nonphotosynthetic diatom and propose that its ATP synthase genes may function in ATP hydrolysis to maintain a proton gradient between thylakoids and stroma, required by the twin arginine translocator (Tat) system for translocation of particular proteins into thylakoids. Given the correlated retention of ATP synthase genes and genes for the Tat system in distantly related nonphotosynthetic plastids, we suggest that this Tat-related role for ATP synthase was a key constraint during parallel loss of photosynthesis in multiple independent lineages of algae/plants.