Prostate Cancer Cell Lines LAPC-4 Research Articles

Increased Notch receptors induces CD8(+) T cell exhaustion in patients with prostate cancer

Objective: To investigate Notch receptor expression in CD8(+) T cells in patients with prostate cancer, and to assess the influence of Notch signaling pathway on the function of CD8(+)T cells inpatients with prostate cancer. Methods: Forty-five patients with prostate cancer, forty-one patients with nonbacterial prostatitis, and thirty healthy controls who were hospitalized or followed-up in Shanxi Provincial People's Hospital between November 2017 and June 2018 were enrolled. CD8(+)T cells were purified, and mRNA relative levels of Notch1-4 were semi-quantified by reverse transcriptional real-time PCR. CD8(+)T cells were stimulated with Notch signaling inhibitor γ-secretase inhibitor (GSI). mRNA relative levels of perforin, granzyme B, and FasL were semi-quantified by reverse transcriptional real-time PCR. Percentages of PD-1 and CTLA-4 positive cells were investigated by flow cytometry. Direct contact and indirect contact coculture systems were set up between CD8(+)T cells and prostate cancer cell line LAPC4 cells. The influence of Notch signaling inhibition to CD8(+)T cell cytotoxicitywas assessed by measuringtarget cell death and cytokine secretion. One-Way ANOVA, LSD-t test, and paired t test was used for comparison. Results: mRNA relative levels of Notch1~4 were elevated in CD8(+)T cells from prostate cancer patients when compared with those from healthy controls and nonbacterial prostatitis patients (all P<0.05). There was CD8(+)T cell exhaustion in prostate cancer patients, which presented as decreased mRNA relative levels of perforin, granzyme B, and FasL (all P<0.000 1), as well as increased percentage of PD-1(+)CD8(+) (19.3%±5.4%) and CTLA-4(+)CD8(+)(11.7%±3.9%) cells. CD8(+)T cells from prostate cancer patients induced LAPC cell death was downregulated in direct contact coculture system (28.8%±6.4% vs 37.2%±2.6%, P=0.015). IFN-γsecretion was also reduced ((61.7±10.6)ng/L vs (88.6±20.2)ng/L, P=0.003 2). Inhibition of Notch signaling by GSI increased mRNA of perforin, granzyme B, and FasL in CD8(+)T cells from prostate cancer patients (all P<0.01), while reduced percentage of PD-1(+)CD8(+)(12.6%±2.5% vs 17.4%±4.7%, P=0.005 9) and CTLA-4(+)CD8(+) (12.0%±1.0% vs 14.1%±3.1%, P=0.011)cells. Notch signaling inhibition promoted LAPC4 cell death (34.3%±7.2%, P=0.000 2) which induced by prostate cancer derived CD8(+)T cells, and increased IFN-γ production ((88.4±33.6)ng/L, P=0.008 3). Conclusion: Elevated Notch receptors induced CD8(+)T cells exhaustion in prostate cancer patients.

3D-Printed Nanoporous Scaffolds Impregnated with Zoledronate for the Treatment of Spinal Bone Metastases

ABSTRACT:Zoledronate (Zol) is a bone-preserving/ anti-tumoral drug that is widely used for the treatment of many cancers including spinal bone metastases. High systemic Zol doses required to elicit an adequate effect in the spine often lead to significant side effects, limiting its prolonged use and effectiveness. Here, we aim to provide an alternative strategy to locally deliver Zol at the tumor site. We show that nanoporous 3D-printed scaffolds can be loaded with Zol and possess the ability to release Zol (10-28%) over a sustained period. Additionally, we demonstrate that Zol-impregnated scaffolds, mostly Gel Lay, impair the proliferation of the prostate cancer cell line LAPC4 and the prostate-induced bone metastasis cells in vitro. 3D-printed nanoporous polymers offer a novel and versatile opportunity for potential local delivery of drugs in future clinical settings. These polymers can decrease systemic exposure and related side effects of Zol while at the same time concentrating the drug effect at the tumor site thereby inhibiting tumor proliferation. Also, these scaffolds could be co-printed or coupled with other materials to produce custom implants that offer better structural support for bone growth at the tumor site following resection.

Low-dose zoledronate for the treatment of bone metastasis secondary to prostate cancer

BackgroundBisphosphonates (BPs) including zoledronate (zol) have become standard care for bone metastases as they effectively inhibit tumor-induced osteolysis and associated pain. Several studies have also suggested that zol has direct anti-tumor activity. Systemic administration at high doses is the current approach to deliver zol, yet it has been associated with debilitating side effects. Local therapeutic delivery offers the ability to administer much lower total dosage, while at the same time maintaining sustained high-local drug concentration directly at the target treatment site. Here, we aimed to assess effects of lower doses of zol on bone metastases over a longer time.MethodsProstate cancer cell line LAPC4 and prostate-induced bone metastasis cells were treated with zol at 1, 3 and 10 µM for 7 days. Following treatment, cell proliferation was assessed using Almarblue®, Vybrant MTT®, and Live/Dead® viability/cytotoxicity assays. Additionally, cell migration and invasion were carried out using Falcon™ cell culture inserts and Cultrex® 3D spheroid cell invasion assays respectively.ResultsWe show that treatment with 3–10 µM zol over 7-days significantly decreased cell proliferation in both the prostate cancer cell line LAPC4 and cells from spine metastases secondary to prostate cancer. Using the same low-dose and longer time course for treatment, we demonstrate that 10 µM zol also significantly inhibits tumor cell migration and 3D-cell growth/invasion.ConclusionsThis project harnesses the potential of using zol at low doses for longer treatment periods, which may be a viable treatment modality when coupled with biomaterials or biodevices for local delivery.

Nanoporous 3D-Printed Scaffolds for Local Doxorubicin Delivery in Bone Metastases Secondary to Prostate Cancer.

The spine is the most common site of bone metastasis, often originating from prostate, lung, and breast cancers. High systemic doses of chemotherapeutics such as doxorubicin (DOX), cisplatin, or paclitaxel often have severe side effects. Surgical removal of spine metastases also leaves large defects which cannot spontaneously heal and require bone grafting. To circumvent these issues, we designed an approach for local chemotherapeutic delivery within 3D-printed scaffolds which could also potentially serve as a bone substitute. Direct treatment of prostate cancer cell line LAPC4 and patient derived spine metastases cells with 0.01 µM DOX significantly reduced metabolic activity, proliferation, migration, and spheroid growth. We then assessed uptake and release of DOX in a series of porous 3D-printed scaffolds on LAPC4 cells as well as patient-derived spine metastases cells. Over seven days, 60–75% of DOX loaded onto scaffolds could be released, which significantly reduced metabolic activity and proliferation of both LAPC4 and patient derived cells, while unloaded scaffolds had no effect. Porous 3D-printed scaffolds may provide a novel and inexpensive approach to locally deliver chemotherapeutics in a patient-specific manner at tumor resection sites. With a composite design to enhance strength and promote sustained drug release, the scaffolds could reduce systemic negative effects, enhance bone repair, and improve patient outcomes.

Nanomicellar TGX221 blocks xenograft tumor growth of prostate cancer in nude mice.

Combination of androgen ablation along with early detection and surgery has made prostate cancer highly treatable at the initial stage. However, this cancer remains the second leading cause of cancer death among American men due to castration-resistant progression, suggesting that novel therapeutic agents are urgently needed for this life-threatening condition. Phosphatidylinositol 3-kinase p110β is a major cellular signaling molecule and has been identified as a critical factor in prostate cancer progression. In a recent report, we established a nanomicelle-based strategy to deliver p110β-specific inhibitor TGX221 to prostate cancer cells by conjugating the surface of nanomicelles with a RNA aptamer against prostate specific membrane antigen (PSMA) present in all clinical prostate cancers. In this study, we tested this nanomicellar TGX221 for its in vivo anti-tumor effect in mouse xenograft models. Prostate cancer cell lines LAPC-4, LNCaP, C4-2 and 22RV1 were used to establish subcutaneous xenograft tumors in nude mice. Paraffin sections from xenograft tumor specimens were used in immunohistochemistry assays to detect AKT phosphorylation, cell proliferation marker Ki67 and proliferating cell nuclear antigen (PCNA), as well as 5-bromo-2-deoxyuridine (BrdU) incorporation. Quantitative PCR assay was conducted to determine prostate-specific antigen (PSA) gene expression in xenograft tumors. Although systemic delivery of unconjugated TGX221 significantly reduced xenograft tumor growth in nude mice compared to solvent control, the nanomicellar TGX221 conjugates completely blocked tumor growth of xenografts derived from multiple prostate cancer cell lines. Further analyses revealed that AKT phosphorylation and cell proliferation indexes were dramatically reduced in xenograft tumors received nanomicellar TGX221 compared to xenograft tumors received unconjugated TGX221 treatment. There was no noticeable side effect by gross observation or at microscopic level of organ tissue section. These data strongly suggest that prostate cancer cell-targeted nanomicellar TGX221 is an effective anti-cancer agent for prostate cancer.

Abstract 3486: Detection of AR W741 mutation in circulating tumor DNA from plasma samples of castration-resistant prostate cancer patients using LNA clamp-mediated PCR.

Abstract After one to two years of hormone therapy, most hormone-dependent prostate cancers become refractory and stop responding to castration treatment. Treatment-emergent mutations in the AR (androgen receptor) gene have been identified in these patients and present a possible mechanism underlying the development of castration-resistant prostate cancer (CRPC). However, since most patient have a biopsy performed only at the time of diagnosis, in general, representative tumor tissue sample giving real time information about the disease status from CRPC patients are missing. The detection of AR mutations in circulating tumor DNA (ctDNA) may be a potential alternative. In this study we validated a locked nucleic acid (LNA) clamp assay for the detection of the AR mutation W741C, known to lead to bicalutamide resistance. The LNA clamp-mediated PCR is based on the blockade of the wildtype (wt) DNA by the LNA, RNA monomers with a modified backbone leading to an increased thermal stability. The identification of the qRT-PCR-enriched mutated DNA (mut) was subsequently performed by sequencing. In a first step, we optimized the annealing and elongation temperatures as well as the concentrations of LNA construct and DNA necessary to achieve the optimal blocker efficiency for the wt, but avoiding blockage of the mut. Therefore we used different concentrations of the genomic wt DNA from the prostate cancer cell line LAPC4. A cell line (KuCaP-1) harboring the W741C mutation was obtained from the group of O. Ogawa (Kyoto University). Using optimized parameters, we were successful in detecting mutated DNA in a ≥ 1000x background of wt DNA. In a second step, we applied the developed assay to clinical plasma samples of 19 CRPC patients, all of whom were receiving bicalutamide treatment except patients 3, 15 and 18. The ctDNA was isolated from plasma using the QIAamp Circulating Nucleic Acid Kit from Qiagen. Three out of nineteen patients were classified as mutation-positive (PID 4, 5, 11). The availability and subsequent sequencing of ctDNA from patient 5 confirmed the existence of the bicalutamide resistance W741 mutation. Due to the small amount of available DNA, sequencing of the mutated ctDNA of patient 4 failed. The ctDNA of patient 11 harbored another SNP in codon 741 leading to a false positive result. In conclusion, our work led to the successful development of a potent LNA clamp-mediated qRT-PCR method for the detection of the bicalutamide resistance mutation W741 in ctDNA of plasma samples. Citation Format: Ines Verena Eggert, Arndt Schmitz, Frank Koenig, Khusru Asadullah, Thomas Krahn, Antje Stresemann. Detection of AR W741 mutation in circulating tumor DNA from plasma samples of castration-resistant prostate cancer patients using LNA clamp-mediated PCR. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3486. doi:10.1158/1538-7445.AM2013-3486

Low-Carbohydrate Diets and Prostate Cancer: How Low Is “Low Enough”?

Previous studies indicate that carbohydrate intake influences prostate cancer biology, as mice fed a no-carbohydrate ketogenic diet (NCKD) had significantly smaller xenograft tumors and longer survival than mice fed a Western diet. As it is nearly impossible for humans to consume and maintain NCKD, we determined whether diets containing 10% or 20% carbohydrate kcal showed similar tumor growth as NCKD. A total of 150 male severe combined immunodeficient mice were fed a Western diet ad libitum, injected with the human prostate cancer cell line LAPC-4, and then randomized 2 weeks later to one of three arms: NCKD, 10% carbohydrate, or 20% carbohydrate diets. Ten mice not injected were fed an ad libitum low-fat diet (12% fat kcal) serving as the reference in a modified-paired feeding protocol. Mice were sacrificed when tumors reached 1,000 mm(3). Despite consuming extra calories, all mice receiving low-carbohydrate diets were significantly lighter than those receiving a low-fat diet (P < 0.04). Among the low-carbohydrate arms, NCKD-fed mice were significantly lighter than the 10% or 20% carbohydrate groups (P < 0.05). Tumors were significantly larger in the 10% carbohydrate group on days 52 and 59 (P < 0.05), but at no other point during the study. Diet did not affect survival (P = 0.34). There were no differences in serum insulin-like growth factor-I or insulin-like growth factor binding protein-3 at sacrifice among the low-carbohydrate arms (P = 0.07 and P = 0.55, respectively). Insulin was significantly lower in the 20% carbohydrate arm (P = 0.03). LAPC-4 xenograft mice fed a low-carbohydrate diet (10-20% carbohydrate kcal) had similar survival as mice consuming NCKD (0% carbohydrate kcal).

Flavokawain B, a kava chalcone, induces apoptosis via up‐regulation of death‐receptor 5 and Bim expression in androgen receptor negative, hormonal refractory prostate cancer cell lines and reduces tumor growth

Limited success has been achieved in extending the survival of patients with metastatic and hormone-refractory prostate cancer (HRPC). There is a strong need for novel agents in the treatment and prevention of HRPC. We have shown that flavokawain B (FKB), a kava chalcone, is about 4- to 12-fold more effective in reducing the cell viabilities of androgen receptor (AR)-negative, HRPC cell lines DU145 and PC-3 than AR-positive, hormone-sensitive prostate cancer cell lines LAPC4 and LNCaP, with minimal effect on normal prostatic epithelial and stromal cells. FKB induces apoptosis with an associated increased expression of proapoptotic proteins: death receptor-5, Bim and Puma and a decreased expression of inhibitors of apoptosis protein: XIAP and survivin. Among them, Bim expression was significantly induced by FKB as early as 4 hr of the treatment. Knockdown of Bim expression by short-hairpin RNAs attenuates the inhibitory effect on anchorage-dependent and -independent growth and caspase cleavages induced by FKB. These findings suggest that the effect of FKB, at least in part, requires Bim expression. In addition, FKB synergizes with TRAIL for markedly enhanced induction of apoptosis. Furthermore, FKB treatment of mice bearing DU145 xenograft tumors results in tumor growth inhibition and increases Bim expression in tumor tissues. Together, these results suggest robust mechanisms for FKB induction of apoptosis preferentially for HRPC and the potential usefulness of FKB for prevention and treatment of HRPC in an adjuvant setting.

Influence of BMPs on the Formation of Osteoblastic Lesions in Metastatic Prostate Cancer

The purpose of this study was to evaluate the role of BMPs on the formation of metastatic prostate cancer lesions to bone. Our results show that BMPs influence the development and progression of osteoblastic lesions and suggest that therapies that inhibit BMP activity may reduce the formation and progression of osteoblastic lesions. Prostate adenocarcinoma is the leading cause of cancer in North American men. The formation of skeletal metastases affects approximately 70% of patients with advanced disease, and a majority of these patients have osteoblastic lesions. Although BMPs have been found to be expressed in multiple oncogenic cell lines, their role in the formation of metastatic osteoblastic lesions remains uncharacterized. We hypothesized that BMPs influence the development of metastatic osteoblastic lesions associated with prostate cancer. Western blot analysis and RT-PCR was used to determine BMP receptor expression on osteoblastic prostate cancer cell lines LAPC-4 and LAPC-9. Migration, invasion, and cellular proliferation assays were used to quantify the effects of BMP-2, -4, and -7 on LAPC-4 cells in vitro. LAPC-9 cells alone or transfected with a retrovirus overexpressing noggin were injected into the tibias of SCID mice, and the animals were followed for 8 weeks. Tumor size was determined by radiographs and direct measurement. Histology was performed at the time of death. We determined that BMP receptor mRNA and protein was expressed on osteoblastic prostate cancer cell lines LAPC-4 and LAPC-9. In vitro studies showed that BMP-2 and -7 stimulated cellular migration and invasion of prostate cancer cells in a dose-dependent fashion, although BMP-4 had no effect. Noggin inhibited cellular migration and invasion of BMP-2- and -7-stimulated LAPC-4 cells. LAPC-9 cells implanted into immunodeficient mouse tibias formed an osteoblastic lesion with sclerotic bone at 8 weeks. Formation of osteoblastic lesions was inhibited by overexpression of noggin by prostate cancer cells transduced with a retrovirus containing the cDNA for noggin. BMPs are critical in the formation of the osteoblastic lesions associated with prostate cancer metastases, and future treatment strategies that inhibit local BMP activity may reduce the formation and progression of osteoblastic lesions.

Loss of CD10 (neutral endopeptidase) is a frequent and early event in human prostate cancer.

We hypothesized that the aggressive LNCaP-derived androgen-independent cell line, CL1, might differ from LNCaP in their repertoire of cell surface markers and that these differences might typify changes that occur during clinical prostate cancer progression. The cell surface marker expression profiles of CL1 and LNCaP were examined using flow cytometry. Markedly differential gene expression was confirmed using RT-PCR and further examined using immunohistochemistry among the prostate cancer cell lines LAPC-4, LNCaP, CL1, CL2, DU145, and PC-3. The expression of the most markedly differentially expressed surface marker, CD10, was further explored in a tissue microarray containing radical prostatectomy samples from 219 hormone naïve prostate cancer patients. There were marked differences in the expression of CD10, CD13, CD26, CD33, CD44, CD54, CD55, and CD104 between CL1 and LNCaP. Results from both the RT-PCR and immunohistochemistry confirmed the differential expression and found that CD10 demonstrated a pattern of expression in hormone sensitive but not hormone refractory cell lines. When CD10 expression was examined in a tissue microarray, CD10 expression was below the 25th percentile of matched normal prostate tissue in 68% of prostate cancers, below the median expression of matched normal prostate tissue in 86% of cancers, and completely absent in 34% of cancers. Samples of prostatic intraepithelial neoplasia demonstrated CD10 expression that was intermediate between normal prostatic tissue and prostate cancer. Among prostate cancer patients, CD10 expression did not correlate with Gleason score, pathological stage, or biochemical recurrence following radical prostatectomy. These findings demonstrate that loss or decreased expression of CD10 is an early and frequent event in human prostate cancer and implicates CD10 as a potential therapeutic target for early stage hormone sensitive prostate cancer.