Effects of tumor-infiltrating lymphocytes on nonresponse rate of neoadjuvant chemotherapy in patients with invasive breast cancer.

High level of tumor-infiltrating lymphocytes (TILs) can predict the rate of total pathological complete remission (tpCR) of breast cancer patients who receive neoadjuvant chemotherapy (NACT). This study focused on evaluating the data of patients whose primary tumor and/or lymph node metastasis show nonresponse (NR) to NACT, trying to provide a basis for the clinical decision which patients will develop NACT resistance. The study included breast cancers from 991 patients who received NACT. ROC curve analysis confirmed that TILs showed significant predictive value for NR of hormone receptor (HR)+HER2- and triple-negative breast cancer (TNBC). Among HR+HER2- breast cancer, TILs ≥ 10% was an independent predictor for low NR rate. Furthermore, positive correlation of TILs with Ki67 index and Miller-Payne grade, and negative correlation with ER and PR H-scores were only identified in this subgroup. In TNBC, TILs ≥ 17.5% was an independent predictor for low NR rate. The predictive value of low TILs on NR may facilitate to screen patients with HR+HER2- or TNBC who may not benefit from NACT. HR+HER2- breast cancer with low levels of TILs should be carefully treated with neoadjuvant chemotherapy, and other alternatives such as neoadjuvant endocrine therapy can be considered.

STAT3 and PD-L1 are negatively correlated with ATM and have impact on the prognosis of triple-negative breast cancer patients with low ATM expression.

INTRODUCTION: Triple-negative breast cancer (TNBC) is known for its aggressive behaviors and lacking of effective treatment. Programmed cell death ligand-1 (PD-L1) inhibitor has just been approved for using in the management of advanced TNBC. To accurately screen TNBC sensitive to anti-PD-L1 treatment and to explore the feasibility of the ataxia-telangiectasia mutation protein (ATM) inhibitor combined with PD-L1 inhibitor, radiotherapy and chemotherapy, we focus on whether ATM participates in the regulation of PD-L1 and affects the prognosis of patients through c-Src, signal transducer and activator of transcription 1&3 (STAT1 and STAT3). MATERIALS AND METHODS: We used immunohistochemical staining to explore the relationship of ATM with c-Src, STAT1, STAT3, PD-1/PD-L1, Tumor-infiltrating lymphocytes (TILs), as well as other clinicopathologic features in 86 pathological stage III TNBCs. Their impact on prognosis was also explored. RESULTS: We found ATM expression was negatively correlated with STAT1, STAT3, PD-L1, TILs and CD8 + cells in TNBC. STAT1 positively correlated the expression of PD-L1. In TNBC with ATM low expression, STAT3 was an independent factor for improved prognosis, while PD-L1 was an independent negative prognostic factor. Furthermore, in low ATM group, the phosphorylation of tyrosine at position 419 of c-Src (p-c-src Y419) was correlated with the overexpression of STAT3. CONCLUSION: Locally advanced TNBC with low ATM expression may be more likely to benefit from anti-PD-L1 inhibitors. The feasibility of ATM functional inhibitor combined with immune checkpoint blockade therapies in the treatment of TNBC is also worthy of further exploration. Our study suggests that STAT3 has different impacts on tumor progression in different tumors.

Building Flexible Escherichia coli Modules for Bifunctionalizing n-Octanol: The Byproduct of Oleic Acid Biorefinery.

Artificial biorefinery of oleic acid into 1,10-decanedioic acid represents a revolutionizing route to the sustainable production of chemically difficult-to-make bifunctional chemicals. However, the carbon atom economy is extremely low (56%) due to the formation of unifunctional n-octanol. Here, we report a panel of recombinant Escherichia coli modules for diverse bifunctionalization, where the desired genetic parts are well distributed into different modules that can be flexibly combined in a plug-and-play manner. The designed ω-functionalizing modules could achieve ω-hydroxylation, consecutive ω-oxidation, or ω-amination of n-octanoic acid. By integrating these advanced modules with the reported oleic acid-cleaving modules, high-value C8 and C10 products, including ω-hydroxy acid, ω-amino acid, and α,ω-dicarboxylic acid, were produced with 100% carbon atom economy. These ω-functionalizing modules enabled the complete use of all of the carbon atoms from oleic acid (released from plant oil) for the green synthesis of structurally diverse bifunctional chemicals.

Engineering Isopropanol Dehydrogenase for Efficient Regeneration of Nicotinamide Cofactors.

Isopropanol dehydrogenase (IPADH) is one of the most attractive options for nicotinamide cofactor regeneration due to its low cost and simple downstream processing. However, poor thermostability and strict cofactor dependency hinder its practical application for bioconversions. In this study, we simultaneously improved the thermostability (433-fold) and catalytic activity (3.3-fold) of IPADH from Brucella suis via a flexible segment engineering strategy. Meanwhile, the cofactor preference of IPADH was successfully switched from NAD(H) to NADP(H) by 1.23 × 106-fold. When these variants were employed in three typical bioredox reactions to drive the synthesis of important chiral pharmaceutical building blocks, they outperformed the commonly used cofactor regeneration systems (glucose dehydrogenase [GDH], formate dehydrogenase [FDH], and lactate dehydrogenase [LDH]) with respect to efficiency of cofactor regeneration. Overall, our study provides two promising IPADH variants with complementary cofactor specificities that have great potential for wide applications. IMPORTANCE Oxidoreductases represent one group of the most important biocatalysts for synthesis of various chiral synthons. However, their practical application was hindered by the expensive nicotinamide cofactors used. Isopropanol dehydrogenase (IPADH) is one of the most attractive biocatalysts for nicotinamide cofactor regeneration. However, poor thermostability and strict cofactor dependency hinder its practical application. In this work, the thermostability and catalytic activity of an IPADH were simultaneously improved via a flexible segment engineering strategy. Meanwhile, the cofactor preference of IPADH was successfully switched from NAD(H) to NADP(H). The resultant variants show great potential for regeneration of nicotinamide cofactors, and the engineering strategy might serve as a useful approach for future engineering of other oxidoreductases.

Enzymatic synthesis of high-titer nicotinamide mononucleotide with a new nicotinamide riboside kinase and an efficient ATP regeneration system.

BACKGROUND: ß-Nicotinamide mononucleotide (NMN) is the direct precursor of nicotinamide coenzymes such as NAD+ and NADP+, which are widely applied in industrial biocatalysis especially involving cofactor-dependent oxidoreductases. Moreover, NMN is a promising candidate for medical uses since it is considered to be beneficial for improving health of aged people who usually suffer from an insufficient level of NAD+. To date, various methods have been developed for the synthesis of NMN. Chemical phosphorylation of nicotinamide riboside (NR) to NMN depends on excessive phosphine oxychloride and delicate temperature control, while fermentation of NMN is limited by low product titers, making it unsuitable for industrial-scale NMN production. As a result, the more efficient synthesis process of NMN is still challenging. AIM: This work attempted to construct an eco-friendly and cost-effective biocatalytic process for transforming the chemically synthesized NR into the highly value-added NMN. RESULTS: A new nicotinamide riboside kinase (Klm-NRK) was identified from Kluyveromyces marxianus. The specific activity of purified Klm-NRK was 7.9 U·mg-1 protein, ranking the highest record among the reported NRKs. The optimal pH of Klm-NRK was 7.0 in potassium phosphate buffer. The purified Klm-NRK retained a half activity after 7.29 h at 50 °C. The catalytic efficiencies (kcat/KM) toward ATP and nicotinamide riboside (NR) were 57.4 s-1·mM-1 and 84.4 s-1·mM-1, respectively. In the presence of an external ATP regeneration system (AcK/AcP), as much as 100 g·L-1 of NR could be completely phosphorylated to NMN in 8 h with Klm-NRK, achieving a molar isolation yield of 84.2% and a space-time yield of 281 g·L-1·day-1. These inspiring results indicated that Klm-NRK is a promising biocatalyst which provides an efficient approach for the bio-manufacturing of NMN in a high titer.

Engineering Bacillus subtilis Isoleucine Dioxygenase for Efficient Synthesis of (2S,3R,4S)-4-Hydroxyisoleucine.

Isoleucine dioxygenase (IDO)-catalyzed hydroxylation of isoleucine is a promising method for the synthesis of the diabetic drug (2S,3R,4S)-4-hydroxyisoleucine [(2S,3R,4S)-4-HIL]. However, the low activity of IDO significantly limits its practical application. In this work, a high-throughput screening method was developed and directed evolution was performed on the IDO from Bacillus subtilis, resulting in a double mutant with improvements in specific activity, protein expression level, and fermentation titer of 3.2-, 2.8-, and 9.4-fold, respectively. l-Isoleucine (228 mM) was completely converted to (2S,3R,4S)-4-HIL by the best variant with a space-time yield of up to 80.8 g L-1 d-1, which is the highest record reported so far. With a further increase of the substrate loading to 1 M, a high conversion of 91% could also be achieved. At last, enzymatic synthesis of (2S,3R,4S)-4-HIL was successfully carried out on a 3 L scale, indicating tremendous potential of the IDO variant I162T/T182N for green and efficient production of (2S,3R,4S)-4-HIL.

Increased number of intratumoral IL-17+ cells, a harbinger of the adverse prognosis of triple-negative breast cancer.

INTRODUCTION: Triple negative breast cancer (TNBC) is an aggressive cancer subtype and lack of effective targeted therapies. It has been recently reported that Interleukin 17 (IL-17), a family of cytokines secreted in tumor microenvironment, affects tumor progression through a variety of molecular pathways. Its role in TNBC is so far still poorly explored. MATERIALS AND METHODS: We employed immunohistochemistry to evaluate the distribution of IL-17+ cells in TNBC with no special type features (TNBC-NST), their association with tumor microangiogenesis, as well as their impact on prognosis of the patients. RESULTS: In comparison to medullary carcinoma with triple-negative molecular features (TNBC-MC), we found a significant increase in IL-17+ cell infiltrates in intratumoral stroma and extratumoral stroma of TNBC-NST. Similarly, stromal cells with co-expression of CD4 and IL-17 were noted in intratumoral and extratumoral stroma in both TNBC-NST and TNBC-MC. In addition, intratumoral IL-17+ cells were positively associated with tumor cell expression of vascular endothelial growth factor A (VEGFA) and with intratumoral tumor microvascular density (MVD). Multivariate analysis identified that intratumoral IL-17+ cells (P = 0.018), MVD (P = 0.039), and TNM stage (P = 0.002) were independent prognostic factors for predicting poor PFS. CONCLUSION: The study indicates that IL-17 is overexpressed in intratumoral stromal cells of TNBC-NST. The overexpression of IL-17 might engage in active tumor microangiogenesis through its signal transduction pathways resulting in increased tumor secretion of VEGFA, and then promote tumor progression. IL-17 might serve as a potential new target for individualized therapy to TNBC-NST patients by development of specific antibodies. Additional study is deemed to further explore the role of IL-17+ stromal cells in breast cancer.

Dasatinib inhibits c-src phosphorylation and prevents the proliferation of Triple-Negative Breast Cancer (TNBC) cells which overexpress Syndecan-Binding Protein (SDCBP).

Triple negative breast cancer (TNBC) progresses rapidly but lacks effective targeted therapies. Our previous study showed that downregulating syndecan-binding protein (SDCBP) in TNBC inhibits the proliferation of TNBC cells. Dasatinib is a new small-molecule inhibitor of c-src phosphorylation. The aim of this study was to investigate if SDCBP is a potential marker to indicate whether a TNBC is suitable for dasatinib therapy. This study applied co-immunoprecipitation to identify the interaction between SDCBP and c-src in TNBC cell lines. In addition, immunohistochemistry was used to investigate SDCBP and tyrosine-419 phosphorylated c-src (p-c-src-Y419) expression in TNBC tissues. SDCBP-overexpressing MDA-MB-231 cells were then constructed to evaluate the effects of dasatinib on SDCBP-induced TNBC progression in vitro and tumor formation in nude mice. We found wild-type SDCBP interacted with c-src and promoted the phosphorylation of c-src; this phosphorylation was completely blocked by dasatinib. SDCBP lacking the PDZ domain had no such effect. Among the 52 consecutive random TNBC cases examined, the expression of SDCBP was consistent with that of p-c-src-Y419, and positively correlated with histological grading or Ki-67 levels. SDCBP overexpression significantly accelerated the proliferation and cell cycle progression of the TNBC cell line MDA-MB-231; these effects were prevented by dasatinib treatment. However, the subsequent inhibition of p27 expression partially restored the proliferation and viability of the TNBC cells. The results of this study suggest that SDCBP interacts with c-src, regulates G1/S in TNBC cells, and enhances tumor cell proliferation by promoting the tyrosine phosphorylation of c-src at residue 419. Dasatinib inhibits such phosphorylation and blocks SDCBP-induced cell cycle progression. Therefore, SDCBP might be an important marker for identifying TNBC cases that are suitable for dasatinib therapy.

Assessment of dual-probe Her-2 fluorescent in situ hybridization in breast cancer by the 2013 ASCO/CAP guidelines produces more equivocal results than that by the 2007 ASCO/CAP guidelines.

Dual-probe fluorescence in situ hybridization (D-FISH) is a widely accepted method to determine the gene amplification status of human epidermal growth factor receptor 2 (Her-2). In 2013, the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) updated the guidelines on the Her-2 testing for invasive breast cancer (BCa). The interpretation criteria for D-FISH changed accordingly. In this study, we compared the Her-2 FISH statuses based on the 2013 and 2007 ASCO/CAP guidelines in 1931 cases of BCa with Her-2 D-FISH testing at our hospital. We analyzed the clinicopathologic features of cases with equivocal results by the 2013 ASCO/CAP guidelines. Although the guideline update significantly improved the detection rate of Her-2 amplification, it also significantly increased the rate of equivocal results, posing a dilemma for clinical management. The equivocal results had a good reproducibility. The distribution of D-FISH-equivocal cases did not correlate with Her-2 status by immunohistochemistry, suggesting that Her-2 D-FISH equivocality may not reflect Her-2 overexpression. Compared with Her-2-negative cases by D-FISH, Her-2 D-FISH-equivocal cases had higher Ki67 expression, higher histological grade, more frequent lymph node metastasis, and lower estrogen receptor α expression, indicating a group of BCa with worse prognosis. The clinical significance of Her-2-equivocal results by D-FISH warrants further investigation.

[Sorption behavior of Triton X-100 on loess and affecting factors].

Batch experiments involving soil-aqueous systems were conducted to determine sorption of Triton X-100 onto natural loess as a function of equilibrium time, Triton X-100 concentration, ionic strength, and pH value. The results showed that the equilibration time for sorption of Triton X-100 onto loess was about 30 min. The sorption kinetics of Triton X-100 fitted well to the pseudo-first-order kinetic model and the corresponding parameters Q(e), k1, and r2 were 3.041 mg x g(-1), 0.102 min(-1), and 0.9934, respectively. Sorption isotherm was found to be distinctly nonlinear. The Sips model provided the best fitting to the experimental data among the four isothermal models tested. Q(max) and r2 of Sips model were 3.202 mg x g(-1) and 0.998 7, respectively. It was found that the ionic strength and the pH of the solution had a significant influence on the sorption of Triton X-100 onto loess. The amount of Triton X-100 sorbed onto the loess increased significantly with increasing concentration of NaCl. Sorption of Triton X-100 onto loess was influenced greatly by pH, the amount of Triton X-100 sorbed decreased as the pH increased.

Syndecan binding protein (SDCBP) is overexpressed in estrogen receptor negative breast cancers, and is a potential promoter for tumor proliferation.

BACKGROUND: Syndecan binding protein (SDCBP), an adapter protein containing PDZ domains, contributes to the tumorigenicity and metastasis of many malignant tumors, such as malignant melanoma. Our study aimed in revealing the expression profile of SDCBP in breast cancer (BCa) and its role in tumor cell proliferation, and then exploring its value in the targeted treatment of BCa. METHODOLOGY/PRINCIPAL FINDINGS: We first evaluated the SDCBP expression by immunohistochemistry in normal breast and BCa tissues. Then we explored the expression profile of SDCBP in different BCa cell lines. By constructing SDCBP-silenced BCa cell clones, we further assessed the effects of SDCBP suppression on tumor cells in vitro by cell culture and in vivo by tumorigenicity. SDCBP expression was detected in 80.6% (n = 160) of BCa tissues, in contrast to its expression in 13% (n = 23) of normal breast tissues (P<0.001). Among the tumors, the level of its expression was positively correlated with histological grade and tumor staging while negatively correlated with the estrogen receptor (ER) expression. Higher expression of SDCBP was also noted in ER-negative BCa cell lines. It was also identified that SDCBP expression was down-regulated in a dose-dependent mode by 17-ß estradiol in estrogen-responsive MCF-7. Furthermore, SDCBP silence inhibited ER-negative tumor cell growth in vivo and in vitro. Cell cycle studies showed that SDCBP silence increased G1 cell population and resulted in related cell-cycle-regulator changes: up-regulation of p21 and p27 while down-regulation of cyclin E. CONCLUSION/SIGNIFICANCE: Our results suggested that SDCBP played an important role in tumor growth of ER-negative BCas. In these tumors where the estrogen signaling pathway is not available, SDCBP probably contribute to tumor growth through an alternative signaling pathway by promoting tumor cells passing the G1/S checkpoint into the cell cycle. Suppression of SDCBP expression may have its potential to become a targeted therapy for ER-negative BCas.

Overexpression of ubiquitous mitochondrial creatine kinase (uMtCK) accelerates tumor growth by inhibiting apoptosis of breast cancer cells and is associated with a poor prognosis in breast cancer patients.

BACKGROUND: Ubiquitous mitochondrial creatine kinase (uMtCK), a mitochondrial isoenzyme of creatine kinase (CK), is a central controller of cellular energy homeostasis. Overexpression of uMtCK has been reported to be associated with a poor prognosis for several tumors. The aim of this study was to assess its association with breast cancer (BCa) and to further investigate its underlying mechanisms. METHOD: We first detected uMtCK expression by immunohistochemistry in human BCa tissues and assessed the association with the prognosis of patients. We then evaluated uMtCK expression in crowded and normal condition cultures of several human BCa cell lines. After two stable clones of the MDA-MB-231 cell line with high expression of uMtCK were established, cell growth, apoptosis and mitochondrial apoptotic pathway protein expression were measured in these clones. Finally, tumorigenicity of the above cells was assessed using nude mice to explore the relationship between uMtCK expression and tumor progression. RESULTS: uMtCK expression was detected in 85.5% (47 of 55) of the invasive ductal carcinomas of breast tissue, not otherwise specified (IDC-NOS). Expression in BCa tissue was significantly associated with reduced progression-free survival (PFS; P=0.019) and overall survival (OS; P=0.022) of the patients. Up-regulation of uMtCK expression was identified in crowded BCa cells in culture, and the number of apoptotic cells was significantly decreased in uMtCK transfected MDA-MB-231 cell clones (P<0.01). Stabilization of the mitochondrial membrane potential (ΔΨm) and down regulation of cytochrome c (cyt c) and activated caspase 9, two components of mitochondrial apoptotic pathway proteins, were also identified in the same clones when cells were crowded in culture. In vivo studies revealed that the transfected tumor cells with uMtCK overexpression induced faster tumor growth in nude mice, along with accelerated animal body weight loss and a significantly lower tumor apoptotic index (AI) (P<0.001). CONCLUSION: The results indicated that uMtCK expression is associated with a poor prognosis in BCa and might serve as a tumor marker. In vivo and In vitro evidence suggests that uMtCK overexpression promotes tumor growth by inhibiting apoptosis of tumor cells through stabilizing ΔΨm and down regulating mitochondrial apoptotic pathway proteins. Exploration of therapeutic agents targeting the expression of uMtCK may have practical value for BCa patients.

[PSCA expression in invasive micropapillary carcinoma of breast].

OBJECTIVE: To study the expression of prostate stem cell antigen (PSCA) at protein and mRNA levels in invasive micropapillary carcinoma of the breast (IMPC) and to analyze the relationship between PSCA expression and clinicopathologic features. METHODS: The expression of PSCA protein was analyzed by immunohistochemistry (LSAB) in 66 cases of IMPC and 67 cases of invasive ductal carcinoma, not otherwise specified (IDC-NOS). The association between PSCA expression and clinicopathologic features was also analyzed in IMPC. Furthermore, RT-PCR was used to detect PSCA mRNA in 10 cases of primary IMPC and 10 cases of primary IDC-NOS with paired normal breast tissues, each from the same subject. RESULTS: Immunohistochemical analysis revealed the overexpression of PSCA in 47 of 66 (71.2%) cases of IMPC and 35 of 67 (52.2%) IDC-NOS. Statistical analysis showed a significant difference of PSCA expression between IMPC and IDC-NOS (P = 0.024). In IMPC, the expression of PSCA was correlated with lymph nodes metastasis (P = 0.039). RT-PCR showed the mRNA level of PSCA was significantly higher in primary IMPC and IDC-NOS tissue than that in paired normal breast tissue (7/10 and 5/10, respectively), and it was also significantly higher in primary IMPC tissue than that in IDC-NOS tissue. CONCLUSION: PSCA might play an important role in lymph node metastasis in IMPC.

Analysis of differentially expressed genes in LNCaP prostate cancer progression model.

The LNCaP/C4-2 human prostate cancer progression model was established to mimic phenotypic and genotypic changes during prostate cancer development from androgen dependence to androgen independence, from nonmetastasis to metastasis. In this study, cDNA microarrays were performed using a microarray chip from Affymetrix to characterize and compare gene expression profiles in LNCaP and C4-2, which may provide novel insight into the molecular mechanism mediating prostate cancer progression. Three hundred eighteen genes consistently exhibited differential expression in LNCaP and C4-2 in 2-time microarray data. Based on their function, the differentially expressed genes can be grouped into several subcategories, including growth factors and signal transducers, oncogenes and tumor suppressors, tumor-specific antigens, transcriptional factors, transporters, and factors involved in invasion, metastasis, and metabolism. Some genes are novel and unexplored in prostate cancer progression and are of potential interest for follow-up investigation. Reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR were performed to corroborate the microarray results, and 76 differentially expressed genes were validated out of 104 candidates. Expression pattern analyses were performed in these 76 differentially expressed genes, and a series of genes was found to be positively or negatively correlated to prostate cancer progression in the LNCaP prostate cancer progression model and to possess predominant prostate cell specificity. ELF5/ESE-2b and long-chain acyl coenzyme A dehydrogenase (ACADL) expressions were found to be positively associated with malignant progression in LNCaP, C4-2, and C4-2B, and predominantly expressed in prostate cancer cells. Functional evaluation revealed that ELF5/ESE-2b and ACADL expressions contributed to the malignant phenotypes of prostate cancer cells. Accordingly, our microarray data may provide clues for finding novel genes involved in prostate cancer progression to androgen independent and metastasis, and shed light on finding new targets for diagnosis and therapy of prostate cancer.

[PC-1 enhances c-myc gene expression in prostate cancer cells].

PC-1(Prostate and colon gene 1) gene belongs to TPD52 (Tumor Protein D52) gene family. The expression of PC-1 is found to promote androgen-independent progression. This study was conducted to assess the mechnism of promotion of androgen-independent progression in PC-1 gene. The c-myc gene expression was tested by RT-PCR and Western blotting analyses in the LNCaP-pc-1 and LNCaP-zero cell line. After separation of cytoplasm and nulear proteins of the LNCaP-pc-1 and LNCaP-zero cell line, the beta-catenin protein was detected by Western blotting. C4-2 cell line was used to examine the effects of 10058-F4 on the PC-1 gene expression. The results of RT-PCR and Western blotting indicated that PC-1 enhanced c-myc gene expression in prostate cancer cells, PC-1 was also found to enhance beta-catenin expression in nuclear. Furthermore, a small-molecule c-Myc inhibitor, 10058-F4 represses PC-1 gene expression in C4-2 cell line. Our findings suggest that PC-1 enhances c-myc gene expression in prostate cancer cells through the Wnt/beta-catenin pathway. Meanwhile, c-myc plays a feed-forward role in enhancing PC-1 driven c-myc gene expression, and promotes prostate an-drogen-independent progression.

[Identification and expression of two new secretory proteins associated with prostate cancer].

Our research intends to obtain extra-cellular proteinogram of cell lines representing different advancement stages of prostate cancer and to test whether screened differential expression proteins can be secreted and used as serum biomarkers for prostate cancer. By examining differential expression spots in two extra-cellular protein 2D-PAGE gels and mass spectrum, candidate molecules were obtained. The expressions of these candidate molecules in eight cell lines and response to androgen stimulus in LNCaP were analyzed by RT-PCR. By constructing eukaryotic expression vectors and western-blotting with anti tags antibodies, the candidate molecules were tested to understand whether they can be expressed in transfected 293T cell culture fluid. Two overexpressed molecules-triosephosphate isomerase 1 (TPI1) and syndecan bind-ing protein, syntenin (ST1)-in extra-cellular proteinogram of C4-2 were screened out; both of them are secretary proteins. On transcriptional level, both proteins were up-regulated with the malignancy of prostate cancer cell lines and ST1 was dose-dependently inhibited by androgen. Considering cellular level results, both TPI1 and ST1 have their potential as serum biomarkers for indicating the developmental stage of prostate cancer.

The radiation response of androgen-refractory prostate cancer cell line C4-2 derived from androgen-sensitive cell line LNCaP.

Radiation therapy is a relatively effective therapeutic method for localized prostate cancer (PCa) patients. However, radioresistance occurs in nearly 30% of patients treated with potentially curative doses. Therapeutic synergy between radiotherapy and androgen ablation treatment provides a promising strategy for improving the clinical outcome. Accordingly, the androgen deprivation-induced signaling pathway may also mediate radiosensitivity in PCa cells. The C4-2 cell line was derived from the androgen-sensitive LNCaP parent line under androgen-depleted condition and had acquired androgen-refractory characteristics. In our study, the response to radiation was evaluated in both LNCaP and C4-2. Results showed that C4-2 cells were more likely to survive from irradiation and appeared more aggressive in their resistance to radiation treatment compared with LNCaP, as measured by clonogenic assays and cell viability and cell cycle analyses. Gene expression analyses revealed that a set of genes involved in cell cycle arrest and DNA repair were differentially regulated in LNCaP and C4-2 in response to radiation, which was also consistent with the radiation-resistant property observed in C4-2 cells. These results strongly suggested that the radiation-resistant property may develop with progression of PCa to androgen-independent status. Not only can the LNCaP and C4-2 PCa progression model be applied for investigating androgen-refractory progression, but it can also be used to explore the development of radiation resistance in PCa.

Ubiquitous mitochondrial creatine kinase is overexpressed in the conditioned medium and the extract of LNCaP lineaged androgen independent cell lines and facilitates prostate cancer progression.

BACKGROUND: Androgen independent prostate cancer (AIPC) is not responsive to androgen ablation therapy. The biomarkers of AIPC are lack. Numerous proteomics studies have focused on finding new markers of AIPC and exploring their possible functions, but little is known about the difference between conditioned medium (CM) from AIPC and androgen dependent prostate cancer (ADPC) cells. METHODS: We performed a proteome analysis of CM from LNCaP, C4-2, and C4-2B cells by a two dimensional electrophoresis based technology. Western blots and immunohistochemical studies were employed to explore the expression pattern of the identified protein in prostate cancer cell lines and clinical specimens, respectively. Then we examined the possible roles and mechanisms of the ubiquitous mitochondrial creatine kinase (uMtCK) in vitro. RESULTS: Besides prostate specific antigen (PSA) and insulin-like growth factor binding protein-2 (IGFBP2), uMtCK was identified in the CM of AIPC cells. uMtCK was up-regulated in AIPC cells and in human prostate cancer tissues at WHO grade III. Stably transfected exogenous uMtCK showed a growth promoting effect rather than mock vector in LNCaP cells, with or without bicalutamide in culture medium. Further assays showed that higher degrees of ROS generation and Akt signaling pathway activation in LNCaP-uMtCK than in LNCaP-neo cells. CONCLUSIONS: We showed that uMtCK could be easily detected in CM of LNCaP lineaged AIPC cells. Exogenous uMtCK in LNCaP cells surprisingly contributed to overproduction of ROS, activation of Akt signaling pathway and more aggressive phenotypes including androgen independence development.