The clinicopathological significance of NAB2-STAT6 gene fusions in 52 cases of intrathoracic solitary fibrous tumors

NAB2-STAT6 gene fusion drives STAT6 nuclear expression and is the pathognomonic hallmark of solitary fibrous tumors (SFTs). However, no study has systematically analyzed the clinicopathological features, STAT6 immunoexpression status, or the fusion variants of NAB2-STAT6 in intrathoracic SFTs. Fifty-two intrathoracic SFTs were retrieved to appraise histopathology, assess STAT6 immunoexpression, and determine NAB2-STAT6 fusion variants by RT-PCR. Location-relevant histologic mimics served as controls. Thirty-one pleura-based, 12 mediastinal/pericardial, and nine intrapulmonary lesions were histologically categorized into eight malignant, eight atypical, and 36 conventional or cellular SFTs, including two fat-forming and two giant cell angiofibroma-like SFTs. STAT6 distinctively decorated the tumoral nuclei in 51 (98%) SFTs. However, no nuclear staining was observed in the histological mimics. NAB2-STAT6 fusion was detected in 34 SFTs. Twenty-nine (85.3%) exhibited the major NAB2ex4-STAT6ex2/3 variant and 5 (14.7%) the minor NAB2ex6-STAT6ex16/17. NAB2ex4-STAT6ex2 was significantly associated with older age (P = 0.01) and pleuropulmonary tumors (P = 0.025). After a median follow-up of 33.9 (range, 0.3-174.6) months, adverse outcomes occurred in one atypical and five malignant SFTs, including two local relapses, one intrapulmonary metastasis, and three extrathoracic metastases. Inferior disease-free survival was univariately associated with atypical/malignant histology (P = 0.001) and a mitosis >4/10 HPFs (P = 0.0012) but was unrelated to fusion variants. In conclusion, the majority of intrathoracic SFTs exhibited STAT6 nuclear staining, and NAB2ex4-STAT6ex2/3 was the predominant fusion type. However, clinical aggressiveness is associated with atypical/malignant histology primarily contributed by increased mitosis but was unrelated to the NAB2-STAT6 fusion variants.

Skp2 deficiency restricts the progression and stem cell features of castration-resistant prostate cancer by destabilizing Twist

Castration-resistant prostate cancer (CRPC) remains a major clinical challenge because of the lack of effective targeted therapy for its treatment. The mechanism underlying how CRPC gains resistance toward hormone depletion and other forms of chemotherapy is poorly understood. Research on understanding the factors that drive these processes is desperately needed to generate new therapies to cure the disease. Here, we discovered a fundamental role of S-phase protein kinase 2 (Skp2) in the formation and progression of CRPC. In transgenic adenocarcinoma mouse prostate model, Skp2 depletion leads to a profound repression of prostate tumor growth and distal metastasis and substantially prolonged overall survival. We revealed that Skp2 regulates CRPC through Twist-mediated oncogenic functions including epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) acquisitions. Mechanistically, Skp2 interacted with Twist and promoted the non-degradative ubiquitination of Twist. Consequently, Skp2 stabilized Twist protein expression by preventing proteasomal degradation of Twist by β-TrCP. We found that Twist overexpression augments CSC self-renewal and population and that Skp2 inhibition reverts Twist's effects on CSC regulation. Furthermore, genetically depleting or pharmacologically inactivating Skp2 synergistically re-sensitized CRPC cells toward chemotherapies such as paclitaxel or doxorubicin. Together, this study uncovering Skp2-mediated Twist stabilization and oncogenic functions in CRPC offers new knowledge on how CRPC progresses and acquires chemoresistance during tumor progression. It provides proof of principle that Skp2 targeting is a promising approach to combat metastatic CRPC by targeting Twist and CSCs.

Anti-IL-20 monoclonal antibody suppresses breast cancer progression and bone osteolysis in murine models

IL-20 is a proinflammatory cytokine involved in rheumatoid arthritis, atherosclerosis, and stroke. However, little is known about its role in breast cancer. We explored the function of IL-20 in tumor growth and metastasis, as well as in clinical outcome. Tumor expression of IL-20 was assessed by immunohistochemical staining among 198 patients with invasive ductal carcinoma of the breast, using available clinical and survival data. IL-20 expression was associated with advanced tumor stage, greater tumor metastasis, and worse survival. Reverse transcription quantitative polymerase chain reaction showed that clinical breast tumor tissue expressed higher levels of IL-20 and its receptors than did nontumorous breast tissue. IL-20 was also highly expressed in breast cancer bone-metastasis tissue. In vitro, IL-20 upregulated matrix metalloproteinase-9, matrix metalloproteinase-12, cathepsin K, and cathepsin G, and enhanced proliferation and migration of breast cancer cells, which were inhibited by anti-IL-20 mAb 7E. In vivo, we generated murine models to evaluate the therapeutic potential of 7E, using luminescence intensity, radiological scans, and micro-computed tomography. 7E reduced tumor growth, suppressed bone colonization, diminished tumor-mediated osteolysis, and lessened bone density decrement in mice injected with breast cancer cells. In conclusion, our results suggest that IL-20 plays pivotal roles in the tumor progression of breast cancer. IL-20 expression in breast cancer tissue is associated with a poor clinical outcome. Anti-IL-20 mAb 7E suppressed bone colonization and decreased osteolytic bone lesions. Therefore, IL-20 may be a novel target in treating breast tumor-induced osteolysis.

Vav3-rac1 signaling regulates prostate cancer metastasis with elevated Vav3 expression correlating with prostate cancer progression and posttreatment recurrence

Prostate cancer remains the second leading cause of cancer death in men in the Western world. Yet current therapies do not significantly improve the long-term survival of patients with distant metastasis. In this study, we investigated the role of the guanine nucleotide exchange factor Vav3 in prostate cancer progression and metastasis and found that Vav3 expression correlated positively with prostate cancer cell migration and invasion. Stimulation of the receptor tyrosine kinase EphA2 by ephrinA1 resulted in recruitment and tyrosine phosphorylation of Vav3, leading to Rac1 activation as well as increased migration and invasion in vitro. Reduction of Vav3 resulted in fewer para-aortic lymph nodes and bone metastasis in vivo. Clinically, expression of Vav3 and EphA2 was elevated in late-stage and metastatic prostate cancers. Among patients with stage IIB or earlier prostate cancer, higher Vav3 expression correlated with lower cumulative biochemical failure-free survival, suggesting that Vav3 may represent a prognostic marker for posttreatment recurrence of prostate cancer. Together, our findings provide evidence that the Vav3-mediated signaling pathway may serve as a therapeutic target for prostate cancer metastasis.

Cycles of ubiquitination and deubiquitination critically regulate growth factor-mediated activation of Akt signaling

K63-linked ubiquitination of Akt is a posttranslational modification that plays a critical role in growth factor-mediated membrane recruitment and activation of Akt. Although E3 ligases involved in growth factor-induced ubiquitination of Akt have been defined, the deubiquitinating enzyme (DUB) that triggers deubiquitination of Akt and the function of Akt deubiquitination remain largely unclear. We showed that CYLD was a DUB for Akt and suppressed growth factor-mediated ubiquitination and activation of Akt. CYLD directly removed ubiquitin moieties from Akt under serum-starved conditions. CYLD dissociated from Akt upon growth factor stimulation, thereby allowing E3 ligases to induce ubiquitination and activation of Akt. CYLD deficiency also promoted cancer cell proliferation, survival, glucose uptake, and, when injected into mice, growth of prostate tumors. Our findings reveal the crucial role of cycles of ubiquitination and deubiquitination of Akt in determining its plasma membrane localization and activation--and further identify CYLD as a molecular switch for these processes.

Metformin promotes apoptosis in hepatocellular carcinoma through the CEBPD-induced autophagy pathway

Metformin, as an AMP-activated protein kinase (AMPK) activator, can activate autophagy. A study showed that metformin decreased the risk of hepatocellular carcinoma (HCC) in diabetic patients. However, the detailed mechanism in the metformin-mediated anticancer effect remains an open question. Transcription factor CCAAT/enhancer-binding protein delta (CEBPD) has been suggested to serve as a tumor suppressor and is responsive to multiple anticancer drugs in HCC. In this study, we found that CEBPD and autophagy are involved in metformin-induced cell apoptosis in Huh7 cells. The underlying mechanisms in this process included a reduction in Src-mediated CEBPD protein degradation and an increase in CEBPD-regulated LC3B and ATG3 gene transcription under metformin treatment. We also found that AMPK is involved in metformin-induced CEBPD expression. Combined treatment with metformin and rapamycin can enhance autophagic cell death through the AMPK-dependent and AMPK-independent pathway, respectively. Taken together, we provide a new insight and therapeutic approach by targeting autophagy in the treatment of HCC.

The E2F transcription factor 1 transactives stathmin 1 in hepatocellular carcinoma

BACKGROUND

Through data mining the Stanford Microarray Database, the stathmin 1 (STMN1) transcript was found to be frequently upregulated in the hepatocellular carcinoma (HCC) with low alpha-fetoprotein level. The molecular mechanism of STMN1 upregulation in HCCs remained unclear.

METHODS

Quantitative RT-PCR, immunoblotting, immunohistochemistry, and transfection of expression or small hairpin RNA interference plasmids, chromatin immunoprecipitation (ChIP), and quantitative ChIP assays were performed in HCC specimens or 2 distinct HCC-derived cell lines. Dual luciferase assay and site-directed mutagenesis were applied to analyze the activities of STMN1 proximal promoter region.

RESULTS

STMN1 mRNA and proteins were significantly associated with several clinicopathological features. High STMN1 or E2F1 immunoexpression was predictive of poor overall survival (OS) rate (P < .01). In HCC-derived cell lines, E2F1 was elevated before STMN1 mRNA during the cell cycle. Exogenous expression of E2F1 or both transcription factor DP-1 (TFDP1) and E2F1 genes induced E2F1 and STMN1 mRNA (P < .01). Knockdown of the E2F1 gene suppressed E2F1 and STMN1 mRNA and E2F1 and STMN1 protein levels (P < .05). The promoter activity of STMN1 gene increased with overexpression of both E2F1 and TFDP1 genes (P < .05); however, it decreased when mutations were introduced in the E2F1-binding sites (P < .05).

CONCLUSIONS

Upregulation of E2F1 and STMN1 proteins associate with worse outcomes in patients with HCC. E2F1 significantly correlates with STMN1 protein level in HCC lesions and in vitro transactivation assays, suggesting that STMN1 gene is transactivated by the E2F1 protein.

Metabolic Stress-Induced Phosphorylation of KAP1 Ser473 Blocks Mitochondrial Fusion in Breast Cancer Cells

Mitochondrial dynamics during nutrient starvation of cancer cells likely exert profound effects on their capability for metastatic progression. Here, we report that KAP1 (TRIM28), a transcriptional coadaptor protein implicated in metastatic progression in breast cancer, is a pivotal regulator of mitochondrial fusion in glucose-starved cancer cells. Diverse metabolic stresses induced Ser473 phosphorylation of KAP1 (pS473-KAP1) in a ROS- and p38-dependent manner. Results from live-cell imaging and molecular studies revealed that during the first 6 to 8 hours of glucose starvation, mitochondria initially underwent extensive fusion, but then subsequently fragmented in a pS473-KAP1-dependent manner. Mechanistic investigations using phosphorylation-defective mutants revealed that KAP1 Ser473 phosphorylation limited mitochondrial hyperfusion in glucose-starved breast cancer cells, as driven by downregulation of the mitofusin protein MFN2, leading to reduced oxidative phosphorylation and ROS production. In clinical specimens of breast cancer, reduced expression of MFN2 corresponded to poor prognosis in patients. In a mouse xenograft model of human breast cancer, there was an association in the core region of tumors between MFN2 downregulation and the presence of highly fragmented mitochondria. Collectively, our results suggest that KAP1 Ser473 phosphorylation acts through MFN2 reduction to restrict mitochondrial hyperfusion, thereby contributing to cancer cell survival under conditions of sustained metabolic stress. Cancer Res; 76(17); 5006-18. ©2016 AACR.

TOP2A overexpression as a poor prognostic factor in patients with nasopharyngeal carcinoma

Despite the advances in diagnostic imaging and treatment modalities, the risk stratification and final outcomes in patients with nasopharyngeal carcinomas (NPC) still remain suboptimal. Through data mining from published transcriptomic database, topoisomerase IIα (TOP2A) was first identified as a differentially upregulated gene in NPC tissues, which implicates cell division via selective cleavage, rearrangement, and re-ligation of DNA strands. Given the roles of TOP2A in prognostication and in the frontline therapeutic regimen of common carcinomas, such as breast cancer, we explored TOP2A immunoexpression status and its associations with clinicopathological variables and survival in a well-defined cohort of NPC patients. TOP2A immunohistochemistry was retrospectively performed and analyzed using H-score method for biopsy specimens from 124 NPC patients who received standard treatment without distant metastasis at initial diagnosis. Those cases with H-score larger than the median value were construed as featuring TOP2A overexpression. The findings were correlated with the clinicopathological variables, disease-specific survival (DSS) and distant metastasis-free survival (DMFS). TOP2A overexpression was significantly associated with American Joint of Cancer Committee (AJCC) stages III-IV (p = 0.019) and univariately predictive of adverse outcomes for DSS (p = 0.0078) and DMFS (p = 0.0003). In the multivariate comparison, TOP2A overexpression remained prognostically independent to portend worse DSS (p = 0.047, hazard ratio = 1.732) and DMFS (p = 0.003, hazard ratio = 2.569), together with advanced AJCC stages III-IV. TOP2A expression is upregulated in a subset of NPCs and its increased immunoexpression significantly correlated with advanced stages and tumor aggressiveness, justifying the potentiality of TOP2A as a prognostic biomarker and a novel therapeutic target of NPC.

Inhibition of the EGFR/STAT3/CEBPD Axis Reverses Cisplatin Cross-resistance with Paclitaxel in the Urothelial Carcinoma of the Urinary Bladder

PURPOSE

Cisplatin (CDDP) is frequently used in combination chemotherapy with paclitaxel for treating urothelial carcinoma of the urinary bladder (UCUB). CDDP cross-resistance has been suggested to develop with paclitaxel, thus hindering successful UCUB treatment. Therefore, elucidating the mechanisms underlying CDDP-induced anticancer drug resistance is imperative and may provide an insight in developing novel therapeutic strategy.

EXPERIMENTAL DESIGN

Loss-of-function assays were performed to elucidate the role of the EGFR and STAT3 in CDDP-induced CCAAT/enhancer-binding protein delta (CEBPD) expression in UCUB cells. Reporter and in vivo DNA-binding assays were employed to determine whether CEBPD directly regulates ATP binding cassette subfamily B member 1 (ABCB1) and ATP binding cassette subfamily C member 2 (ABCC2) activation. Finally, a xenograft animal assay was used to examine the abilities of gefitinib and S3I-201 (a STAT3 inhibitor) to reverse CDDP and paclitaxel sensitivity.

RESULTS

CEBPD expression was maintained in postoperative chemotherapy patients, and this expression was induced by CDDP even in CDDP-resistant UCUB cells. Upon CDDP treatment, CEBPD activated ABCB1 and ABCC2. Furthermore, the EGFR/STAT3 pathway contributed to CDDP-induced CEBPD expression in UCUB cells. Gefitinib and S3I-201 treatment significantly reduced the expression of CEBPD and enhanced the sensitivity of CDDP-resistant UCUB cells to CDDP and paclitaxel.

CONCLUSIONS

Our results revealed the risk of CEBPD activation in CDDP-resistant UCUB cells and suggested a therapeutic strategy for patients with UCUB or UCUB resisted to CDDP and paclitaxel by combination with either gefitinib or S3I-201. Clin Cancer Res; 23(2); 503-13. ©2016 AACR.

Inhibition of HDAC3- and HDAC6-Promoted Survivin Expression Plays an Important Role in SAHA-Induced Autophagy and Viability Reduction in Breast Cancer Cells

SAHA is a class I HDAC/HDAC6 co-inhibitor and an autophagy inducer currently undergoing clinical investigations in breast cancer patients. However, the molecular mechanism of action of SAHA in breast cancer cells remains unclear. In this study, we found that SAHA is equally effective in targeting cells of different breast cancer subtypes and tamoxifen sensitivity. Importantly, we found that down-regulation of survivin plays an important role in SAHA-induced autophagy and cell viability reduction in human breast cancer cells. SAHA decreased survivin and XIAP gene transcription, induced survivin protein acetylation and early nuclear translocation in MCF7 and MDA-MB-231 breast cancer cells. It also reduced survivin and XIAP protein stability in part through modulating the expression and activation of the 26S proteasome and heat-shock protein 90. Interestingly, targeting HDAC3 and HDAC6, but not other HDAC isoforms, by siRNA/pharmacological inhibitors mimicked the effects of SAHA in modulating the acetylation, expression, and nuclear translocation of survivin and induced autophagy in MCF7 and MDA-MB-231 cancer cells. Targeting HDAC3 also mimicked the effect of SAHA in up-regulating the expression and activity of proteasome, which might lead to the reduced protein stability of survivin in breast cancer cells. In conclusion, this study provides new insights into SAHA's molecular mechanism of actions in breast cancer cells. Our findings emphasize the complexity of the regulatory roles in different HDAC isoforms and potentially assist in predicting the mechanism of novel HDAC inhibitors in targeted or combinational therapies in the future.

Upregulated IL-19 in breast cancer promotes tumor progression and affects clinical outcome

PURPOSE

Interleukin (IL)-19 was expressed in invasive ductal carcinoma (IDC) of the breast tissue but not in healthy breast tissue. We explored the effects of IL-19 on the pathogenesis of breast cancer and its clinical outcome.

EXPERIMENTAL DESIGN

Tumor expression of IL-19 was assessed by immunohistochemistry and/or real-time quantitative PCR between two groups of patients with breast IDC (n = 60 and 143, respectively) with available clinical and survival data. We examined the effects of IL-19 on cytokine and chemokine production as well as proliferation and migration in breast cancer cells. Mice were injected with IL-19-overexpressing or vector control 67NR cells and the tumor growth and lung metastatic micronodules were measured.

RESULTS

Of the IDC specimens, high IL-19 expression was associated with advanced tumor stage, high tumor metastasis, and worse survival. In vitro, IL-19 induced transcripts of IL-1β, IL-6, TGF-β, matrix metalloproteinase (MMP)2, MMP9, and CXCR4 in 4T1 breast cancer cells; induced fibronectin expression and assembly; and promoted cancer cell proliferation and migration, which were inhibited by anti-IL-19 monoclonal antibody (mAb). Endogenous fibronectin expression and cancer cell migration were lower in IL-19 knockdown 4T1 cells. In 4T1 cells, hypoxia induced IL-19 and CXCR4 expression, which was inhibited by anti-IL-19 mAb. IL-19 overexpression in noninvasive 67NR cancer cells increased cell proliferation and migration. In vivo, mice injected with IL-19-overexpressing 67NR cell clones showed larger tumors and more metastatic micronodules in the lung.

CONCLUSIONS

High IL-19 expression in breast cancer tissue is associated with a poor clinical outcome. IL-19 is pivotal in the pathogenesis of breast cancer.

Targeting chemotherapy-induced PTX3 in tumor stroma to prevent the progression of drug-resistant cancers

The tumor microenvironment has been suggested to participate in tumorigenesis, but the nature of the communication between cancer cells and the microenvironment, especially in response to anticancer drugs, remains obscure. We determined that activation of the CCAAT/enhancer binding protein delta (CEBPD) response to Cisplatin and 5-Fluorouracil in cancer-associated macrophages and fibroblasts contributed to the metastasis, invasion, acquired chemoresistance and stemness of cancer cells by in vitro and in vivo assays. Specifically, reporter and in vivo DNA binding assays were used to determine that Pentraxin 3 (PTX3) is a CEBPD responsive gene and serves a protumor role upon anticancer drug treatment. Finally, a PTX3 peptide inhibitor RI37 was developed and assessed the antitumor effects by in vivo assays. RI37 could function as a promising inhibitor for preventing cancer progression and the metastasis, invasion and progression of drug-resistant cancers. The identification of PTX3 provided a new insight in the interaction between host and tumor and the RI37 peptide showed a great opportunity to largely reduce the risk of invasion and metastasis of cancer and drug-resistant cancers.

ZBRK1 acts as a metastatic suppressor by directly regulating MMP9 in cervical cancer

The BRCA1-interacted transcriptional repressor ZBRK1 has been associated with antiangiogenesis, but direct evidence of a tumor suppressor role has been lacking. In this study, we provide evidence of such a role in cervical carcinoma. ZBRK1 levels in cervical tumor cells were significantly lower than in normal cervical epithelial cells. In HeLa cervical cancer cells, enforced expression inhibited malignant growth, invasion, and metastasis in a variety of in vitro and in vivo assays. Expression of the metalloproteinase MMP9, which is known to be an important driver of invasion and metastasis, was found to be inversely correlated with ZBRK1 in tumor tissues and a target for repression in tumor cells. Our findings suggest that ZBRK1 acts to inhibit metastasis of cervical carcinoma, perhaps by modulating MMP9 expression.

Angiomatoid fibrous histiocytoma: clinicopathological and molecular characterisation with emphasis on variant histomorphology

AIMS

Angiomatoid fibrous histiocytoma (AFH) is histologically typified by nodules of histiocytoid spindle cells with pseudoangiomatoid spaces, fibrous pseudocapsules and lymphocytic cuffs. The principal goal was to expand the spectrum of AFHs through clinicopathological and molecular characterisation.

METHODS

Thirteen AFHs, including 11 with confirmed hallmark translocation, were reappraised for classic features, reactive osteoclasts, mitoses and stromal, architectural and cytomorphological variations, with CD99, desmin and EMA stained in available cases.

RESULTS

Seven male and six female patients ranged in age from 4 to 63 years (median, 13), including 4 older than 20 years. Tumours were located on the extremities (n=6), trunk (n=4) and scalp (n=3). Although fibrous pseudocapsules were observed in all cases, four showed solid histology without pseudoangiomatoid spaces and another one lacked peripheral lymphoid infiltrates. Nuclear pleomorphism was striking in two cases, moderate in seven and absent in four, with osteoclasts seen in two cases. In three AFHs with sclerotic matrix, one exhibited perivascular hyalinisation and nuclear palisading, reminiscent of a schwannoma. In three varyingly myxoid tumours, one closely resembled a myoepithelioma with prominent reticular arrangement of spindle cells in an abundant myxoid stroma. Besides EWSR1 gene rearrangement detected in four cases by fluorescence in situ hybridisation (FISH), EWSR1-CREB1 fusion was confirmed in nine cases, including a schwannoma-like AFH, and EWSR1-ATF1 fusion detected in a myoepithelioma-like AFH. Immunohistochemically, 56% of AFHs were positive for EMA, 78% for desmin and 100% for CD99.

CONCLUSIONS

Molecular testing is diagnostic of variant AFHs displaying diverse histomorphological alterations in the architectural patterns, cytomorphology and extracellular matrix.

Lysine demethylase 2A promotes stemness and angiogenesis of breast cancer by upregulating Jagged1

Alterations of histone methylation dynamically regulated by methyltransferases and demethylases are frequently found in human cancers. Here, we showed that expression of lysine demethylase 2A (KDM2A) is markedly increased in human breast cancer and its overexpression is associated with tumor progression and poor prognosis. Knockdown of KDM2A in breast cancer cells reduced proliferation but not viability. Gene set enrichment analysis revealed that inhibition of KDM2A down-regulates angiogenic genes with concurrent reduction of Jagged1 (JAG1), NOTCH1 and HEY1 in the NOTCH signaling. Chromatin immunoprecipitation- quantitative polymerase chain reaction (ChIP-qPCR) demonstrated the binding of KDM2A to the JAG1 promoter and the increase of methylation of Lys-36 of histone H3 (H3K36) in KDM2A-depleted MDA-MB-231 cells. Tumorsphere formation was significantly reduced in KDM2A-depleted cells which could be reversed by ectopic expression of JAG1. A selective KDM2A inhibitor daminozide also decreased the number of tumorsphere and the number of CD24-/CD44hi cells. In addition, daminozide acted synergistically with cisplatin in cell killing. We identified SOX2 as a direct transcriptional target of KDM2A to promote cancer stemness. Depletion of KDM2A in MDA-MB-231 cells attenuated NOTCH activation and tube formation in co-cultured endothelial cells. Two pro-angiogenic factors JAG1 and PDGFA are key mediators for KDM2A to enhance angiogenesis. Finally, inhibition of KDM2A significantly decreased tumor growth and angiogenesis in orthotopic animal experiments. Collectively, we conclude that KDM2A functions as an oncogene in breast cancer by upregulating JAG1 to promote stemness, chemoresistance and angiogenesis.

Deficiency in expression and epigenetic DNA Methylation of ASS1 gene in nasopharyngeal carcinoma: negative prognostic impact and therapeutic relevance

The risk stratification and final outcomes in patients with nasopharyngeal carcinomas (NPC) still remain suboptimal. Our principal goals were to identify and validate targetable metabolic drivers relevant to pathogenesis of NPC using a published transcriptome. One prominently downregulated gene regulating amino acid metabolism was found to be argininosuccinate synthetase (ASS1). Attributable to epigenetic DNA methylation, ASS1 deficiency may link to the therapeutic sensitivity to the arginine-depriving agents and promote tumor aggressiveness through its newly identified tumor suppressor function. ASS1 immunohistochemistry was therefore examined in a well-defined cohort of 124 NPC biopsy specimens and in the neck lymph node metastases of another ten independent cases. For the latter, bisulphite pyrosequencing was performed to evaluate the extent of ASS1 gene methylation. ASS1 protein deficiency was identified in 64 of 124 cases (51.6%), significantly related to T3-T4 status (p = 0.006), and univariately associated with inferior local recurrence-free survival (p = 0.0427), distant metastasis-free survival (DMFS; p = 0.0036), and disease-specific survival (DSS; p = 0.0069). Together with advanced AJCC stages III-IV, ASS1 protein deficiency was also independently predictive of worse outcomes for the DFMS (p = 0.010, hazard ratio = 2.241) and DSS (p = 0.020, hazard ratio = 1.900). ASS1 promoter hypermethylation was detected in eight of ten neck nodal metastatic lesions by bisulphite pyrosequencing and associated with ASS1 protein deficiency (p < 0.001). In summary, ASS1 protein deficiency was seen in approximately a half of NPCs and associated with advanced T classification, DNA methylation, and clinical aggressiveness, consistent with its tumor suppressor role. This aberration may render pegylated arginine deiminase as a promising strategy for ASS1-deficient NPCs.

Clinicopathological and genetic heterogeneity of the head and neck solitary fibrous tumours: a comparative histological, immunohistochemical and molecular study of 36 cases

AIMS

Solitary fibrous tumour (SFT) harbours recurrent inv12(q13q13)-derived NAB2-STAT6 fusions, resulting in STAT6 nuclear expression. SFTs affecting the head and neck are rare, for which we reported their clinicopathological, immunohistochemical, and genetic features.

METHODS AND RESULTS

With 19 cases assessable for NAB2-STAT6 fusions, 36 head and neck SFTs (18 males; 18 females) diagnosed between 13 and 79 years (median, 47 years) of age were analysed for clinicopathological features and STAT6 immunoexpression. These SFTs, ranging from 5 to 80 mm (median, 25 mm), affected the oral cavity/pharynx (12), orbit (11), sinonasal structures (seven), and somatic soft tissues or skull (six). Histologically, 20 SFTs were conventional, six were giant-cell angiofibroma-like, one was fat-forming, four were cellular/atypical, and five were malignant (two developing metastases). STAT6 distinctively decorated the tumoral nuclei in 35 (97.2%) SFTs, but not in 29 site-relevant histological mimics categorized into 12 entities. Sixteen (84.2%) SFTs showed NAB2-STAT6 fusions with highly heterogeneous exon compositions, including NAB2ex6-STAT6ex17 in four cases, NAB2ex4-STAT6ex2 in three cases, NAB2ex2-STAT6ex2, NAB2ex4-STAT6ex4, NAB2ex6-STAT6ex16 and NAB2ex6-STAT6ex18 in two cases each, and NAB2ex3-STAT6ex19 in one case.

CONCLUSIONS

Nuclear STAT6 immunoexpression is sensitive and specific for distinguishing SFT from mimics. However, considerable heterogeneity exists in the head and neck SFTs regarding the locations, histological patterns, and NAB2-STAT6 fusion variants.

Activin A enhances prostate cancer cell migration through activation of androgen receptor and is overexpressed in metastatic prostate cancer

Bone metastasis is the major cause of mortality associated with prostate cancer. Whereas activin A is known to inhibit prostate cancer cell growth and promote apoptosis, the correlation of elevated activin A with increasing serum prostate-specific antigen (PSA) levels in bone metastatic stages of prostate cancer is well documented. The molecular mechanisms explaining these paradoxical effects of activin A and how activin A influences the progression of prostate cancer with bone metastasis remain unclear. By comparing expression profiles of primary prostate cancer biopsies, with and without bone metastasis, we discovered that the expression of activin A is increased in cases with bone metastatic propensity and correlates with increased androgen receptor (AR), PSA expression, and Gleason scores. Activin A promotes migration of prostate cancer cells to osteoblasts, elevates the AR gene transcription through Smads through binding to AR promoter, and induces nuclear translocation of AR to interact with Smad3. Knockdown of Smad3 by siRNA decreases activin A-promoted AR expression and cancer cell migration. Overexpression of AR reversed Smad3-siRNA suppression on activin A-mediated cell migration to osteoblasts. These data suggest that activation of the AR through Smads is required for activin A-promoted prostate cancer cell migration to bone matrix, thereby promoting the bone metastatic phenotype, and the activin A-Smad-AR axis may be considered a therapeutic target in bone metastatic diseases.

Primary urothelial carcinoma of the upper tract: important clinicopathological factors predicting bladder recurrence after surgical resection

The aim of the present study was to further characterize potential clinicopathological predictors for urinary bladder recurrence-free survival (UBRFS) in patients with primary urothelial carcinoma of the upper urinary tract (UUT-UC). The present series included 385 cases of surgically treated primary localized UUT-UC without previous or concurrent urothelial carcinoma of the urinary bladder. Among the 374 patients with follow-up information, clinicopathological features and therapeutic information including whether they received a laparoscopy-assisted nephroureterectomy (LNU) and adjuvant chemotherapy were correlated with UBRFS. After a median follow up of 69 months, 86 patients (23%) developed urinary bladder recurrence. The median time to develop urinary bladder recurrence was 12 months. At the univariate level, an increment in histological grade (P= 0.0321), a prominent papillary configuration (P= 0.0004), LNU (P= 0.0397) and male gender (P= 0.0401) significantly predicted an inferior UBRFS. At the multivariate level, increase of histological grade (P < 0.0001, relative risk (RR) = 3.776), prominent papillary configuration (P < 0.0001, RR = 3.244), and male gender (P= 0.0463, RR = 1.444) independently predicted UBRFS. In conclusion, male patients and those with high-grade and papillary UUT-UC, and who received LNU had higher risks of urinary bladder recurrence. Accordingly, for these patients, more intensive follow up coupled with postoperative intravesical adjuvant therapy to prevent urinary bladder recurrence should also be considered.

Immunohistochemical expression of p16INK4A, Ki-67, and Mcm2 proteins in gastrointestinal stromal tumors: prognostic implications and correlations with risk stratification of NIH consensus criteria

BACKGROUND

Inactivation of p16(INK4A) promotes G1/S progression of cell cycle. Minichromosome maintenance protein-2 (Mcm2), a novel cell proliferation marker, is known to better correlate with clinical outcomes than Ki-67 in many carcinomas. Since gastrointestinal stromal tumors (GISTs) sometimes remains challenging in prognostication, we analyzed the utility of these three markers in GISTs.

METHODS

Immunohistochemistry was performed in tissue microarrays of 277 primary GISTs and correlated with NIH consensus criteria and clinical outcomes.

RESULTS

The increment of NIH risk levels significantly correlated with increasing labeling indices (LI) of both Ki-67 (P <.001) and Mcm2 (P <.001) and loss of p16(INK4A) expression (P <.035). However, the latter aberration did occur in 23% of very low/low-risk GISTs. The relationship between Mcm2 and Ki-67 LIs could be modeled as linear (P <.001, r = 0.697), while Mcm2 LI was considerably higher (P <.001) with a stepwise escalation related to risk levels. Ki-67 LI >5% (P <.0001) and Mcm2 LI >10% (P <.0001) were strongly predictive of inferior disease-specific survival (DSS), while aberrant loss of p16(INK4A) only reached a trend (P = .0954). In multivariate analyses, independent adverse factors of DSS were high-risk category (RR = 16.93, P <.0001), metastatic disease (RR = 4.12, P = .0015), Ki-67 LI >5% (RR = 3.55, P = .001), and presence of epithelioid histology (RR = 2.17, P = .0308).

CONCLUSIONS

Prognostic efficacy of NIH consensus criteria is substantiated. P16(INK4A) deregulation can occur early in GIST tumorigenesis and marginally correlates with patient survival. Despite Ki-67 LI being an independent prognosticator, simultaneous detection of Mcm2 is recommended as a prognostic adjunct of GISTs, given its better sensitivity and stepwise escalation with increasing risk levels.

Skp2 overexpression is highly representative of intrinsic biological aggressiveness and independently associated with poor prognosis in primary localized myxofibrosarcomas

PURPOSE

Two SCF(Skp2) ubiquitin ligase-related proteins, Skp2 and cyclin-dependent kinase subunit 1 (Cks1), are involved in posttranscriptional degradation of p27(Kip1) tumor suppressor. We analyzed the prognostic utility of p27(Kip1) and its interacting cell cycle regulators in myxofibrosarcomas.

EXPERIMENTAL DESIGN

Clinicopathologic features and tissue microarray-based immunohistochemical expression of p27(Kip1), Skp2, Cks1, cyclin E, cyclin A, Ki-67, and minichromosome maintenance protein 2 (Mcm2) were assessed in 70 primary myxofibrosarcomas and correlated with clinical outcomes. Skp2 mRNA expression and the relationship between Skp2 and p27(Kip1) proteins were examined in six cases by semiquantitative reverse transcription-PCR and Western blotting, respectively.

RESULTS

High indices of Skp2 (> or =10%), cyclin A (> or =10%), and Mcm2 (> or =50%) were adverse prognosticators at the univariate level. Furthermore, co-overexpression of Skp2 and cyclin A identified highly lethal cases in the entire cohort [P < 0.0001 for disease-specific survival (DSS), P = 0.0004 for overall survival (OS)] and the lower-grade subset (Fédération Nationale des Centres de Lutte Contre le Cancer grade 1 and 2; P = 0.0006 for DSS, P = 0.0093 for OS). In multivariate analyses, Skp2 overexpression overshadowed most intrinsic clinicopathologic factors and independently correlated with worse metastasis-free survival (P = 0.0012), DSS (P = 0.0234), and OS (P = 0.0056). Notably, positive margins independently predicted inferior local recurrence-free survival (P = 0.0012) and also negatively affected metastasis-free survival (P = 0.0471), DSS (P = 0.0152), and OS (P = 0.0173). Reverse transcription-PCR showed up-regulation of Skp2 mRNA in four cases and Western blotting displayed a matched expression pattern of Skp2.

CONCLUSIONS

Margin status and intrinsic property of myxofibrosarcomas both affect patient survival. Skp2 overexpression is highly representative of the biological aggressiveness of myxofibrosarcomas and plays an important prognostic role.

Transplantation of autologous endothelial progenitor cells in porous PLGA scaffolds create a microenvironment for the regeneration of hyaline cartilage in rabbits

OBJECTIVE

Repairing articular cartilage is clinically challenging. We investigated a simple, effective and clinically feasible cell-based therapeutic approach using a poly(lactide-co-glycolide) (PLGA) scaffold seeded with autologous endothelial progenitor cells (EPC) to repair a full-thickness osteochondral defect in rabbits using a one-step surgery.

METHODS

EPC obtained by purifying a small amount of peripheral blood from rabbits were seeded into a highly porous, biocompatible PLGA scaffold, namely, EPC-PLGA, and implanted into the osteochondral defect in the medial femoral condyle. Twenty two rabbits were randomized into one of three groups: the empty defect group (ED), the PLGA-only group or the EPC-PLGA group. The defect sites were evaluated 4 and 12 weeks after implantation.

RESULTS

At the end of testing, only the EPC-PLGA group showed the development of new cartilage tissue with a smooth, transparent and integrated articular surface. Moreover, histological analysis showed obvious differences in cartilage regeneration. At week 4, the EPC-PLGA group showed considerably higher TGF-β2 and TGF-β3 expression, a greater amount of synthesized glycosaminoglycan (GAG) content, and a higher degree of osteochondral angiogenesis in repaired tissues. At week 12, the EPC-PLGA group showed enhanced hyaline cartilage regeneration with a normal columnar chondrocyte arrangement, higher SOX9 expression, and greater GAG and collagen type II (COLII) content. Moreover, the EPC-PLGA group showed organized osteochondral integration, the formation of vessel-rich tubercular bone and significantly higher bone volume per tissue volume and trabecular thickness (Tb.Th).

CONCLUSION

The present EPC-PLGA cell delivery system generates a suitable in situ microenvironment for osteochondral regeneration without the supplement of exogenous growth factors.

Malignant diffuse-type tenosynovial giant cell tumors: a series of 7 cases comparing with 24 benign lesions with review of the literature

BACKGROUND

Malignant diffuse-type tenosynovial giant cell tumor (D-TSGCT), an unusual sarcoma with concurrent or previous benign D-TSGCTs, poses challenges to diagnosis and prognostication.

METHODS

We described the radiologic, clinicopathologic, and immunophenotypical findings of 5 primary and 2 metachronous malignant D-TSGCTs and reviewed published cases to better delineate their morphologic spectrum and behavior. Twenty-four benign D-TSGCTs were also statically compared to analyze the diagnostic values of various variables.

RESULTS

The 7 malignant cases affected 4 females and 3 males aged 45 to 78 (mean, 60.9) years, which included 1 intraarticular and 6 extra-articular lesions. These tumors were 5 to 17 cm (mean, 9.4) and located within or near the large joints of extremities. Magnetic resonance imaging revealed expansile or infiltrative masses with frequent lobulation and heterogeneous signals. Histologically, areas of benign D-TSGCTs blended abruptly or gradually with frank sarcomas composed of pleomorphic, spindle, or enlarged oval cells, forming malignant fibrous histiocytomalike (n = 4), fibrosarcomatous (n = 1), myxosarcomatous (n = 1), or giant cell tumorlike (n = 1) patterns. One patient experienced recurrences twice, and another 3 developed metastases to the lymph nodes (n = 2), lung (n = 1), or vertebrae (n = 1), with 1 dying from disseminated diseases. An older age (P = 0.003), a larger size (P = 0.036), tumor necrosis (P < 0.001), atypical mitoses (P < 0.001), and Ki-67 overexpression (P < 0.001) appeared preferentially in malignant lesions, but these parameters had overlap between few benign and malignant tumors.

CONCLUSIONS

Malignant D-TSGCTs are a distinct sarcoma with considerable morphologic variability, metastatic propensity, and lethality. Altered architecture with anaplastic cells represents an important distinguishing feature, while abnormalities of other parameters should not be directly equated with malignancy.

CCAAT/enhancer binding protein δ in macrophages contributes to immunosuppression and inhibits phagocytosis in nasopharyngeal carcinoma

Although tumors tend to be associated with immune cells and inflammation, this immune response often fails to eliminate the cancer and instead promotes cancer progression. Tumor-associated macrophages (TAMs) fail to phagocytose tumor cells, and they also produce signals that suppress the adaptive immune response. We showed that immunosuppressive prostaglandin E₂ (PGE₂) led to the production and activity of the transcription factor CCAAT/enhancer binding protein δ (C/EBPδ) by stimulating the nucleocytoplasmic shuttling of the RNA binding protein Hu antigen R (HuR), which bound to and stabilized CEBPD mRNA in macrophages. An increase in C/EBPδ abundance in macrophages in response to PGE₂ resulted in enhanced production of the immunosuppressive cytokine interleukin-10 (IL-10) and of pentraxin 3 (PTX3), which suppresses the ability of macrophages to phagocytose tumor cells. Furthermore, conditioned medium from C/EBPδ-replete, but not C/EBPδ-deficient, macrophages inhibited the phagocytosis of tumor cells by macrophages, suggesting an autocrine mode of regulation. Immunohistochemical analysis demonstrated that the amount of cytosolic HuR protein correlated with increased C/EBPδ abundance in TAMs in malignant nasopharyngeal carcinoma. Together, these data suggest that the inflammatory PGE₂-HuR-C/EBPδ axis in macrophages promotes tumor progression by preventing the phagocytosis of tumor cells and inducing immunosuppressive cytokine production.