Autophagic reliance promotes metabolic reprogramming in oncogenic KRAS-driven tumorigenesis

Defects in basal autophagy limit the nutrient supply from recycling of intracellular constituents. Despite our understanding of the prosurvival role of macroautophagy/autophagy, how nutrient deprivation, caused by compromised autophagy, affects oncogenic KRAS-driven tumor progression is poorly understood. Here, we demonstrate that conditional impairment of the autophagy gene Atg5 (atg5-KO) extends the survival of KRASG12V-driven tumor-bearing mice by 38%. atg5-KO tumors spread more slowly during late tumorigenesis, despite a faster onset. atg5-KO tumor cells displayed reduced mitochondrial function and increased mitochondrial fragmentation. Metabolite profiles indicated a deficiency in the nonessential amino acid asparagine despite a compensatory overexpression of ASNS (asparagine synthetase), key enzyme for de novo asparagine synthesis. Inhibition of either autophagy or ASNS reduced KRASG12V-driven tumor cell proliferation, migration, and invasion, which was rescued by asparagine supplementation or knockdown of MFF (mitochondrial fission factor). Finally, these observations were reflected in human cancer-derived data, linking ASNS overexpression with poor clinical outcome in multiple cancers. Together, our data document a widespread yet specific asparagine homeostasis control by autophagy and ASNS, highlighting the previously unrecognized role of autophagy in suppressing the metabolic barriers of low asparagine and excessive mitochondrial fragmentation to permit malignant KRAS-driven tumor progression.

SKP2 overexpression is associated with a poor prognosis of rectal cancer treated with chemoradiotherapy and represents a therapeutic target with high potential

The S-phase kinase-associated protein 2 (SKP2) oncoprotein is an E3 ubiquitin ligase. Overexpression of SKP2 was found in various human cancers, including colorectal cancers, but its potential role as a prognostic marker after neoadjuvant chemoradiotherapy (CRT) and for therapeutic intervention in rectal cancers is unknown. This study examined the correlation of SKP2 expression in the prognosis of rectal cancer patients and the viability of colorectal cancer cells treated with CRT. SKP2 immunoexpression was retrospectively assessed in pretreatment biopsies of 172 rectal cancer patients treated with neoadjuvant CRT followed by surgery. Results were correlated with clinicopathological features, therapeutic responses, and patient survival. Pharmacologic assays were used to evaluate the therapeutic relevance of Bortezomib in two colorectal cancer cell lines (HT-29 and SW480). High expression of SKP2 was correlated with the advanced Post-Tx nodal status (p = 0.002), Post-Tx International Union for Cancer Control stage (p = 0.002), and a lower-degree tumor regression grade (p < 0.001). Moreover, high expression of SKP2 (p = 0.027, hazard ratio 3.21) was an independent prognostic factor for local recurrence-free survival. In vitro, Bortezomib downregulated SKP2 expression, induced caspase activation, and decreased the viability of colorectal cancer cells with or without a combination with fluorouracil. Bortezomib also promoted caspase activation and gamma-H2AX formation in colorectal cancer cells concurrently treated with CRT. High expression of SKP2 was associated with a poor therapeutic response and adverse outcomes in rectal cancer patients treated with neoadjuvant CRT. In the presence of chemotherapy with or without radiotherapy, the promoted sensitivity of colorectal cancer cells to Bortezomib with an SKP2-repressing effect indicated that it is a potential therapeutic target.

SPOCK1 Overexpression Confers a Poor Prognosis in Urothelial Carcinoma

PURPOSE

The majority deaths of cancer patients are related to metastasis, thus genes associated with cell motility interest us. SPOCK1 was elected by data mining and serial evaluation. In addition, SPOCK1 has been reported to be highly expressed in different human cancers and been related to adverse outcomes. Therefore, we validate its prognostic significance in urothelial carcinoma (UC).

MATERIALS AND METHODS

Real-time RT-PCR assay was used to detect SPOCK1 transcript level in 27 urinary tract urothelial carcinoma (UTUC) and 27 urinary bladder urothelial carcinoma (UBUC) samples. Immunohistochemistry evaluated by H-score determined SPOCK1 expressions in 340 UTUCs and 295 UBUCs. The transcript and protein expression were correlated with clinicopathological features. Further evaluations of the prognostic significance of SPOCK1 for disease-specific survival (DSS) and metastasis-free survival (MeFS) were analyzed.

RESULTS

The expressions of SPOCK1 in UC were higher than those in normal urothelium by immunohistochemistry. The statistical analysis of clinicopathologic characteristics and immunohistochemistry showed that the higher expression of SPOCK1 was correlated to pT status (P<0.001), lymph node metastasis (UTUC, P=0.006; UBUC, P=0.033), higher histological grade (UTUC, P<0.001; UBUC, P<0.001), vascular invasion (UTUC, P<0.001; UBUC, P<0.001), perineurial invasion (UTUC, P<0.001; UBUC, P=0.001) and frequent mitosis (UTUC, P<0.001; UBUC, P=0.001). The prognosis of SPOCK1 of UC showed high SPOCK1 expression had significantly worse DSS and MeFS.

CONCLUSIONS

The investigation demonstrated that the higher expression of SPOCK1 correlates with a poor prognosis in UC.

Shiunko and acetylshikonin promote reepithelialization, angiogenesis, and granulation tissue formation in wounded skin

Shiunko is a traditional botanic formula (ointment) used clinically for treating wounded skin. The aim of the present study was to compare the effects of Shiunko and acetylshikonin, and its active ingredient, with those of gentamicin and silver sulfadiazine ointments, two disinfectants for wound healing. Wounds were cut in the backs of Sprague-Dawley rats. Different bacterial inoculations (Pseudomonas aeruginosa and Staphylococcus aureus) and treatments (Shiunko, acetylshikonin, gentamicin, silver sulfadiazine, and vehicle ointments) were used to treat these wounds. We found that rats treated with Shiunko and acetylshikonin on both the sterilized and infected wounds showed higher rates of reepithelialization than those treated with the other ointments (p < 0.05) during a 7-day observation. In the histological study, rats treated with Shiunko and acetylshikonin on both the sterilized and infected wounds showed greater reepithelialization, angiogenesis, and granulation tissue formation than rats treated with the other ointments (p < 0.05) on day 5 after the wounds had been sutured. Differences between rats treated with Shiunko and acetylshikonin ointments were not statistically significant. In conclusion, topically applying Shiunko and acetylshikonin on wounded skin promoted wound healing. Both ointments were effective on sterilized and infected wounds.

Overexpression of a chromatin remodeling factor, RSF-1/HBXAP, correlates with aggressive oral squamous cell carcinoma

RSF-1, also known as hepatitis B X-antigen associated protein (HBXAP), is a subunit of an ISWI chromatin remodeling complex, remodeling and spacing factor (RSF). Recent studies have provided new evidence that chromatin remodeling participates in the pathogenesis of neoplastic diseases by altering cell cycle regulation and gene expression. In this report, we studied the biological roles of RSF-1 in oral squamous cell carcinoma (OSCC), a highly invasive neoplastic disease. Based on IHC and quantitative real-time PCR, we demonstrated that RSF-1 expression could be detected in the majority of OSCC cases, and the levels were significantly higher in OSCC cells than in their normal counterparts. Moreover, expression levels of RSF-1 significantly correlated with the presence of angiolymphatic invasion, abnormal mitoses, metastasis, tumor recurrence, and advanced stage disease at presentation. Univariate and multivariate analyses showed a significant association of RSF-1 overexpression and worse overall survival in OSCC patients. RSF-1 knockdown remarkably decreased cellular proliferation and induced apoptosis in OSCC cells with high RSF-1 expression levels, but not in those without. Taken together, our results suggest that RSF-1 up-regulation is associated with several clinicopathological features of disease aggressiveness in OSCC patients, and RSF-1 plays an important role in maintaining cellular growth and survival in OSCC.

Nicotinamide N-methyltransferase overexpression is associated with Akt phosphorylation and indicates worse prognosis in patients with nasopharyngeal carcinoma

Nicotinamide N-methyltransferase (NNMT) is overexpressed in many human cancers and is associated with poor prognosis. Akt (also known as protein kinase B) is an evolutionarily conserved serine/threonine kinase, serving as a downstream effector of the phosphatidylinositol 3-kinase signaling pathway. NNMT was first identified as a differentially upregulated gene in nasopharyngeal cancer tissues through data mining from published transcriptomic databases. Since no prior study has attempted to evaluate the clinical significance of NNMT or phosphorylated Akt (pAkt) expression in nasopharyngeal cancer, this study explores their expression in a large cohort of patients with nasopharyngeal cancer. The study included 124 nasopharyngeal cancer patients who were free of distant metastasis at initial diagnosis. Pathological slides were reviewed and clinical findings collected. We evaluated the expression of NNMT and pAkt immunohistochemically, stratified them into two groups (high and low expression) and examined the correlation with disease-specific survival (DSS), metastasis-free survival (MeFS), local recurrence-free survival (LRFS), and various clinicopathological factors. NNMT expression was significantly positively associated with pAkt expression. The high expression of both markers was significantly associated with an increment of tumor stage (p = 0.006 and p = 0.006, respectively). High expression of NNMT correlated significantly with a more aggressive clinical course and a significantly shorter DSS. Furthermore, NNMT expression and pAkt expression were strongly predictive of MeFS (p = 0.008; p = 0.0063) and LRFS (p = 0.005; p = 0.0125). In multivariate analysis, high expression of NNMT remained as a robust prognosticator for both end points evaluated. It independently portended inferior DSS (p = 0.02, HR = 1.976) and worse MeFS (p = 0.029, HR = 2.022) after tumor stage (p = 0.033, HR = 2.150; p = 0.028, HR = 2.942, for DSS and LRFS, respectively). We found NNMT positively correlated with pAkt expression and was independent adverse prognosticators of patient survival. NNMT therefore has potential utility as an indicator for prognosis, predicting treatment response to chemotherapy or radiation therapy, and even as a therapeutic target in the future.

Heat shock protein 90 overexpression independently predicts inferior disease-free survival with differential expression of the alpha and beta isoforms in gastrointestinal stromal tumors

PURPOSE

Most gastrointestinal stromal tumors harbor a mutated KIT or PDGFRA receptor tyrosine kinase (RTK). Heat shock protein 90 (Hsp90) is a chaperone mediating the folding and stabilization of many oncoproteins, including KIT. An Hsp90 inhibitor, 17-AAG, can attenuate KIT activation and proliferation of gastrointestinal stromal tumor cell lines. We further evaluated Hsp90 immunoexpression and the difference between alpha and beta isoforms in gastrointestinal stromal tumor specimens.

EXPERIMENTAL DESIGN

Hsp90 immunostain was assessable in 306 cases on tissue microarrays of primary gastrointestinal stromal tumors and correlated with various variables and disease-free survival (DFS). RTK mutation variants, confirmed in 142 cases by sequencing with or without precedent denaturing high pressure liquid chromatography screening, were dichotomized into two prognostically different groups. Differential expression of transcript and protein isoforms was measured by real-time reverse transcription-PCR and Western blotting in 16 and 6 cases, respectively.

RESULTS

Hsp90 overexpression (55%) significantly correlated with larger size, nongastric location, higher mitotic count and NIH risk level, Ki-67 overexpression (all P < or = 0.001), and unfavorable RTK genotypes (P = 0.020). It strongly portended inferior DFS univariately (P < 0.0001) and remained independent in multivariate analysis (P = 0.031; risk ratio, 2.44), along with high-risk category, Ki-67 overexpression, and old age. For both mRNA and protein, Hsp90beta was more abundant than Hsp90alpha, whereas the latter was significantly higher in high-risk cases.

CONCLUSIONS

Hsp90 overexpression represents a poor prognosticator that correlates with several adverse parameters, highlighting its role in disease progression and alternative therapy for high-risk, imatinib-resistant gastrointestinal stromal tumors. Hsp90alpha seems more relevant to the intrinsic aggressiveness of gastrointestinal stromal tumors, albeit less abundant than Hsp90beta.

AMACR amplification in myxofibrosarcomas: a mechanism of overexpression that promotes cell proliferation with therapeutic relevance

PURPOSE

Myxofibrosarcomas frequently display arm-level gains on 5p. We characterized the pathogenetic and therapeutic relevance of the α-methylacyl coenzyme A racemase (AMACR) at 5p13.3.

EXPERIMENTAL DESIGN

AMACR mRNA expression in myxofibrosarcomas was analyzed using the public transcriptome and laser-microdissected sarcoma cells. We performed florescence in situ hybridization (FISH) and immunohistochemistry in independent samples for clinical correlates. In AMACR-overexpressing myxofibrosarcoma cells and xenografts, we elucidated the biologic function of AMACR using RNA interference and explored the therapeutic effect and mechanism of an AMACR inhibitor, ebselen oxide.

RESULTS

AMACR protein overexpression and gene amplification were significantly associated with each other (P < 0.001), with higher tumor grades (both P ≤ 0.002), and univariately with worse metastasis-free survival (MFS; both P < 0.0001) and disease-specific survival (DSS; P = 0.0002 for overexpression; P = 0.0062 for amplification). AMACR protein overexpression also independently portended adverse outcome (DSS, P = 0.007; MFS, P = 0.001). However, 39% of AMACR-overexpression cases did not show gene amplification, implying alternative regulatory mechanisms. In myxofibrosarcoma cell lines, stable AMACR knockdown suppressed cell proliferation, anchorage-independent growth, and expression of cyclin D1 and cyclin T2. These growth-promoting attributes of AMACR were corroborated in the AMACR-silenced xenograft model and AMACR-underexpressed myxofibrosarcomas, showing decreased labeling for cyclin D1, cyclin T2, and Ki-67. Compared with fibroblasts, AMACR-expressing myxofibrosarcoma cells were more susceptible to ebselen oxide, which not only decreased viable cells, promoted proteasome-mediated degradation of AMACR protein, and induced cellular apoptosis in vitro, but also dose-dependently suppressed xenografted tumor growth in vivo.

CONCLUSIONS

Overexpressed AMACR in myxofibrosarcomas can be amplification-driven, associated with tumor aggressiveness, and may be relevant as a druggable target.

Annexin-I overexpression is associated with tumour progression and independently predicts inferior disease-specific and metastasis-free survival in urinary bladder urothelial carcinoma

AIMS

In our previous studies, comparative proteomics and immunohistochemistry (IHC) demonstrated that annexin-I (ANXA1) is up-regulated in high grade urinary bladder urothelial carcinoma (UBUC) as compared to non-high grade carcinomas. However, the small sample size prohibited further correlation of ANXA1 expression to tumour progression. Therefore, in the present study, 81 primary localised UBUC specimens of various grades and primary tumour (pT) status were examined for ANXA1 expression to further confirm the proteomics data and to clarify the relevance of ANXA1 expression level to the prognosis of UBUC.

METHODS

IHC was implemented to investigate ANXA1 protein expression in 81 primary localised UBUC specimens. The association of ANXA1 expression with tumour progression and prognosis was analysed.

RESULTS

Our data demonstrated that the ANXA1 expression level was strongly associated with an escalated pT status (p < 0.001) and a higher histological grade (p < 0.001), suggesting that ANXA1 might be related to tumour progression. Moreover, at the univariate level, ANXA1 overexpression, along with higher pT status and histological grade, significantly predicted disease-specific survival (DSS) and metastasis-free survival (MFS). More importantly, multivariate analyses revealed that the association of ANXA1 overexpression and prognosis remained significant for both DSS and MFS.

CONCLUSION

The above results reinforced the comparative proteomics results and confirmed the prognostic role of ANXA1 in UBUC.

The prognostic impact of lipid biosynthesis-associated markers, HSD17B2 and HMGCS2, in rectal cancer treated with neoadjuvant concurrent chemoradiotherapy

Neoadjuvant concurrent chemoradiotherapy has been widely used for rectal cancer to improve local tumor control. The varied response of individual tumors encouraged us to search for useful biomarkers to predict the therapeutic response. The study was aimed to evaluate the prognostic impact of lipid biosynthesis-associated biomarkers in rectal cancer patients treated with preoperative chemoradiotherapy. Through analysis of the previously published gene expression profiling database focusing on genes associated with lipid biosynthesis, we found that HSD17B2 and HMGCS2 were the top two significantly upregulated genes in the non-responders. We further evaluated their expression by immunohistochemistry in the pre-treatment tumor specimens from 172 patients with rectal cancer and statistically analyzed the associations between their expression and various clinicopathological factors, as well as survival. High expression of HMGCS2 or HSD17B2 was significantly associated with advanced pre- and post-treatment tumor or nodal status (P < 0.001) and lower tumor regression grade (P < 0.001). More importantly, high expression of either HMGCS2 or HSD17B2 was of prognostic significance, with HMGCS2 overexpression indicating poor prognosis for disease-free survival (P = 0.0003), local recurrence-free survival (P = 0.0115), and metastasis-free survival (P = 0.0119), while HSD17B2 overexpression was associated with poor prognosis for disease-free survival (P <0.0001), local recurrence-free survival (P = 0.0009), and metastasis-free survival (P < 0.0001). In multivariate analysis, only HSD17B2 overexpression remained as an independent prognosticator for shorter disease-free survival (P < 0.001) and metastasis-free survival (P = 0.008). In conclusion, high expression of either HSD17B2 or HMGCS2 predicted poor susceptibility of rectal cancer to preoperative chemoradiotherapy. Both acted as promising prognostic factors, particularly HSD17B2.

Overexpression of thymidylate synthetase confers an independent prognostic indicator in nasopharyngeal carcinoma

Data mining on public domain identified that thymidylate synthetase (TYMS) and dihydrofolate reductase (DHFR) transcripts were significantly higher expressed in nasopharyngeal carcinoma (NPC). In the folate pathway, TYMS catalyzes the methylation of deoxyuridylate to deoxythymidylate using 5,10-methylenetetrahydrofolate [5,10-CH2=THF, derived from tetrahydrofolate (THF)], as a cofactor. This function maintains the thymidine-5-prime monophosphate pool critical for DNA replication and repair and, THF is generated from dihydrofolate (DHF) through the activity of DHFR. Immunoexpression of TYMS and DHFR were retrospectively assessed in biopsies of 124 consecutive NPC patients without initial distant metastasis and treated with consistent guidelines. The outcome was correlated with clinicopathological features and patient survivals. Results indicated that high TYMS (50%) expressions were correlated with primary tumor (p=0.008) and AJCC stage (p=0.006), and high DHFR (50%) expression were correlated with nodal status (p=0.039) and AJCC stage (p=0.029) (7th American Joint Committee on Cancer), respectively. In multivariate analyses, high TYMS expression emerged as an independent prognosticator for worse disease-specific survival (p<0.001), distal metastasis-free survival (p=0.002) and local recurrence-free survival (p<0.001), along with AJCC stage. Therefore, TYMS expression is common and associated with adverse prognosticators and might confer tumor aggressiveness through dysregulation of the nucleotide biosynthetic process.

Differentiation between Glioblastoma Multiforme and Primary Cerebral Lymphoma: Additional Benefits of Quantitative Diffusion-Weighted MR Imaging

The differentiation between glioblastoma multiforme (GBM) and primary cerebral lymphoma (PCL) is important because the treatments are substantially different. The purpose of this article is to describe the MR imaging characteristics of GBM and PCL with emphasis on the quantitative ADC analysis in the tumor necrosis, the most strongly-enhanced tumor area, and the peritumoral edema. This retrospective cohort study collected 104 GBM (WHO grade IV) patients and 22 immune-competent PCL (diffuse large B cell lymphoma) patients. All these patients had pretreatment brain MR DWI and ADC imaging. Analysis of conventional MR imaging and quantitative ADC measurement including the tumor necrosis (ADCn), the most strongly-enhanced tumor area (ADCt), and the peritumoral edema (ADCe) were done. ROC analysis with optimal cut-off values and area-under-the ROC curve (AUC) was performed. For conventional MR imaging, there are statistical differences in tumor size, tumor location, tumor margin, and the presence of tumor necrosis between GBM and PCL. Quantitative ADC analysis shows that GBM tended to have significantly (P<0.05) higher ADC in the most strongly-enhanced area (ADCt) and lower ADC in the peritumoral edema (ADCe) as compared with PCL. Excellent AUC (0.94) with optimal sensitivity of 90% and specificity of 86% for differentiating between GBM and PCL was obtained by combination of ADC in the tumor necrosis (ADCn), the most strongly-enhanced tumor area (ADCt), and the peritumoral edema (ADCe). Besides, there are positive ADC gradients in the peritumoral edema in a subset of GBMs but not in the PCLs. Quantitative ADC analysis in these three areas can thus be implemented to improve diagnostic accuracy for these two brain tumor types. The histological correlation of the ADC difference deserves further investigation.

BCAT1 overexpression is an indicator of poor prognosis in patients with urothelial carcinomas of the upper urinary tract and urinary bladder

AIMS

Amino acid biosynthesis is one of the cardinal events of carcinogenesis that has not been investigated in urothelial carcinoma (UC). By data-mining a published transcriptomic database of UCs of urinary bladder (UBUCs) (GSE31684), we identified branched-chain amino acid transaminase 1 (BCAT1) as the most significantly stepwise up-regulated gene during tumour progression among those associated with the amino acid biosynthetic process (GO:0008652). Accordingly, we analysed BCAT1 transcript and protein expression with their clinicopathological significance.

METHODS AND RESULTS

We used real-time reverse transcription-polymerase chain reaction (RT-PCR) to detect BCAT1 transcript levels in 20 UCs of upper tract (UTUCs) and 20 UBUCs, respectively. Immunohistochemical study was performed to determine BCAT1 protein expression in 340 UTUCs and 295 UBUCs. Higher BCAT1 transcript levels were associated with higher pT status in both groups (P < 0.05). BCAT1 protein overexpression was also associated significantly with adverse clinicopathological features, e.g. advanced pT stage, nodal metastasis, high pathological grade, etc. (P < 0.05). BCAT1 overexpression predicted worse disease-specific survival and metastasis-free survival in both univariate and multivariate analyses (P ≤ 0.001).

CONCLUSION

BCAT1 overexpression is associated with advanced tumour status, and implies adverse clinical outcomes of UCs, suggesting that its role in tumour progression could serve as a prognostic biomarker and a novel therapeutic target in UC.

The cAMP responsive element binding protein 1 transactivates epithelial membrane protein 2, a potential tumor suppressor in the urinary bladder urothelial carcinoma

In this study, we report that EMP2 plays a tumor suppressor role by inducing G2/M cell cycle arrest, suppressing cell viability, proliferation, colony formation/anchorage-independent cell growth via regulation of G2/M checkpoints in distinct urinary bladder urothelial carcinoma (UBUC)-derived cell lines. Genistein treatment or exogenous expression of the cAMP responsive element binding protein 1 (CREB1) gene in different UBUC-derived cell lines induced EMP2 transcription and subsequent translation. Mutagenesis on either or both cAMP-responsive element(s) dramatically decreased the EMP2 promoter activity with, without genistein treatment or exogenous CREB1 expression, respectively. Significantly correlation between the EMP2 immunointensity and primary tumor, nodal status, histological grade, vascular invasion and mitotic activity was identified. Multivariate analysis further demonstrated that low EMP2 immunoexpression is an independent prognostic factor for poor disease-specific survival. Genistein treatments, knockdown of EMP2 gene and double knockdown of CREB1 and EMP2 genes significantly inhibited tumor growth and notably downregulated CREB1 and EMP2 protein levels in the mice xenograft models. Therefore, genistein induced CREB1 transcription, translation and upregulated pCREB1(S133) protein level. Afterward, pCREB1(S133) transactivated the tumor suppressor gene, EMP2, in vitro and in vivo. Our study identified a novel transcriptional target, which plays a tumor suppressor role, of CREB1.

Autophagy is involved in endogenous and NVP-AUY922-induced KIT degradation in gastrointestinal stromal tumors

Gastrointestinal stromal tumor (GIST) is a prototype of mutant KIT oncogene-driven tumor. Prolonged tyrosine kinase inhibitor (TKI) treatment may result in a resistant phenotype through acquired secondary KIT mutation. Heat shock protein 90 (HSP90AA1) is a chaperone protein responsible for protein maturation and stability, and KIT is a known client protein of HSP90AA1. Inhibition of HSP90AA1 has been shown to destabilize KIT protein by enhancing its degradation via the proteasome-dependent pathway. In this study, we demonstrated that NVP-AUY922 (AUY922), a new class of HSP90AA1 inhibitor, is effective in inhibiting the growth of GIST cells expressing mutant KIT protein, the imatinib-sensitive GIST882 and imatinib-resistant GIST48 cells. The growth inhibition was accompanied with a sustained reduction of both total and phosphorylated KIT proteins and the induction of apoptosis in both cell lines. Surprisingly, AUY922-induced KIT reduction could be partially reversed by pharmacological inhibition of either autophagy or proteasome degradation pathway. The blockade of autophagy alone led to the accumulation of the KIT protein, highlighting the role of autophagy in endogenous KIT turnover. The involvement of autophagy in endogenous and AUY922-induced KIT protein turnover was further confirmed by the colocalization of KIT with MAP1LC3B-, acridine orange- or SQSTM1-labeled autophagosome, and by the accumulation of KIT in GIST cells by silencing either BECN1 or ATG5 to disrupt autophagosome activity. Therefore, the results not only highlight the potential application of AUY922 for the treatment of KIT-expressing GISTs, but also provide the first evidence for the involvement of autophagy in endogenous and HSP90AA1 inhibitor-induced KIT degradation.

Fatty acid synthase overexpression confers an independent prognosticator and associates with radiation resistance in nasopharyngeal carcinoma

Fatty acid synthase (FASN) is overexpressed in many human cancers and associated with poor prognosis. However, the role of FASN in nasopharyngeal carcinoma (NPC) has not been studied. We evaluated the expression of FASN immunohistochemically in 124 NPC specimens, stratified them into two groups (FASN-high and FASN-low), and examined the correlation with various clinicopathological parameters. In two NPC cell lines, HONE1 and TW01, we targeted the FASN transcript by shRNAi and evaluated the effect on cell proliferation by WST-1 assay and radiation-induced apoptosis by measuring caspase-3 and caspase-7 activation. NPC with high FASN immunoexpression was correlated with advanced pT disease status and worse prognosis in terms of disease-specific survival, metastasis-free survival and local recurrence-free survival, compared to FASN-low group in both univariate and multivariate analyses. In the two NPC cell lines, endogenous FASN expression was significantly higher than the non-tumor keratinocyte, DOK. When the expression of FASN was suppressed by shRNAi, the tumor cells showed decreased cell proliferation and increased apoptosis after radiation. Our results supported FASN as an adverse prognostic marker in NPC, possibly by conferring cell growth advantage and resistance to radiation-induced apoptosis on tumor cells. The inhibition of FASN expression might be investigated as an adjunct in treatment, especially in radiation resistant NPC.

Prognostic implication of MET overexpression in myxofibrosarcomas: an integrative array comparative genomic hybridization, real-time quantitative PCR, immunoblotting, and immunohistochemical analysis

It remains obscure in myxofibrosarcoma about the basis of tumorigenesis, progression, and metastasis. Chromosome 7 gains are common in some sarcomas, including myxofibrosarcoma, whereas the specific oncogenes are yet to be characterized. We performed an integrative study of MET gene at 7q31.2 to elucidate its implication in myxofibrosarcoma. Focused on candidate oncogenes on chromosome 7, 385K array comparative genomic hybridization was used to profile DNA copy number alterations of 12 samples. MET transcript was successfully quantified by real-time RT-PCR for 16 laser-microdissected tumors and two myxofibrosarcoma cell lines (NMFH-1, OH931). MET immunoexpression was assessable in 86 primary localized tumors with follow-up. To analyze endogenous MET expression and activation, NMFH-1 and OH931 cells, both with wild-type MET gene, were subjected to Western blotting and hepatocyte growth factor-treated NMFH-1 cells were evaluated for the kinetics of MET tyrosine phosphorylation. Non-random large-scale gains on 7q were detected in five cases, delineating three recurrent amplicons, 7q21.11-7q21.3, 7q22.1-22.3, and 7q31.1-7q32.3, in which the locus of MET displayed increased copy number, among others. MET mRNA was upregulated in OH931, NMFH-1, and nine tumors (56%), whereas neither gene dosage nor mRNA expression of MET was associated with clinicopathological factors. In contrast, MET protein overexpression, present in 67% of cases, was highly related to deep location (P=0.004), higher grades (P=0.001), and more advanced stages (P<0.001). Importantly, MET overexpression independently portended inferior metastasis-free survival (P=0.004) and overall survival (P=0.0221). Expressing activating phospho-MET at Tyr(1234)/Tyr(1235), OH931 cells had more abundant total MET than NMFH-1 cells, whereas the latter became promptly phosphorylated on stimulation of hepatocyte growth factor. In primary myxofibrosarcomas, MET overexpression, as a frequent event, is likely driven by 7q gains with mRNA upregulation, associated with important prognosticators, and independently predictive of worse outcomes, highlighting its possible causative function in tumor aggressiveness and potentiality as a therapeutic target.

Metformin Resensitizes Sorafenib-Resistant HCC Cells Through AMPK-Dependent Autophagy Activation

Despite the activation of autophagy may enable residual cancer cells to survive and allow tumor relapse, excessive activation of autophagy may eventually lead to cell death. However, the details of the association of autophagy with primary resistance in hepatocellular carcinoma (HCC) remain less clear. In this study, cohort analysis revealed that HCC patients receiving sorafenib with HBV had higher mortality risk. We found that high epidermal growth factor receptor (EGFR) expression and activity may be linked to HBV-induced sorafenib resistance. We further found that the resistance of EGFR-overexpressed liver cancer cells to sorafenib is associated with low activity of AMP-activated protein kinase (AMPK) and CCAAT/enhancer binding protein delta (CEBPD) as well as insufficient autophagic activation. In response to metformin, the AMPK/cAMP-response element binding protein (CREB) pathway contributes to CEBPD activation, which promotes autophagic cell death. Moreover, treatment with metformin can increase sorafenib sensitivity through AMPK activation in EGFR-overexpressed liver cancer cells. This study suggests that AMPK/CEBPD-activated autophagy could be a potent strategy for improving the efficacy of sorafenib in HCC patients.

Transmembrane and Coiled-Coil Domain 1 Impairs the AKT Signaling Pathway in Urinary Bladder Urothelial Carcinoma: A Characterization of a Tumor Suppressor

Purpose: Urinary bladder urothelial carcinoma (UBUC) is a common malignant disease in developed countries. Cell-cycle dysregulation resulting in uncontrolled cell proliferation has been associated with UBUC development. This study aimed to explore the roles of TMCO1 in UBUCs.Experimental Design: Data mining, branched DNA assay, immunohistochemistry, xenograft, cell culture, quantitative RT-PCR, immunoblotting, stable and transient transfection, lentivirus production and stable knockdown, cell-cycle, cell viability and proliferation, soft-agar, wound-healing, transwell migration and invasion, coimmunoprecipitation, immunocytochemistry, and AKT serine/threonine kinase (AKT) activity assays and site-directed mutagenesis were used to study TMCO1 involvement in vivo and in vitroResults: Data mining identified that the TMCO1 transcript was downregulated during the progression of UBUCs. In distinct UBUC-derived cell lines, changes in TMCO1 levels altered the cell-cycle distribution, cell viability, cell proliferation, and colony formation and modulated the AKT pathway. TMCO1 recruited the PH domain and leucine-rich repeat protein phosphatase 2 (PHLPP2) to dephosphorylate pAKT1(serine 473) (S473). Mutagenesis at S60 of the TMCO1 protein released TMCO1-induced cell-cycle arrest and restored the AKT pathway in BFTC905 cells. Stable TMCO1 (wild-type) overexpression suppressed, whereas T33A and S60A mutants recovered, tumor size in xenograft mice.Conclusions: Clinical associations, xenograft mice, and in vitro indications provide solid evidence that the TMCO1 gene is a novel tumor suppressor in UBUCs. TMCO1 dysregulates cell-cycle progression via suppression of the AKT pathway, and S60 of the TMCO1 protein is crucial for its tumor-suppressor roles. Clin Cancer Res; 23(24); 7650-63. ©2017 AACR.

FGF7 Over Expression is an Independent Prognosticator in Patients with Urothelial Carcinoma of the Upper Urinary Tract and Bladder

PURPOSE

Urothelial carcinoma of the bladder and upper tract is the most common tumor type in the urinary tract but its molecular pathogenesis and survival determinants remain obscure. By data mining a published transcriptomic database of bladder urothelial carcinoma (GSE31684) we identified FGF7 as the most significant gene up-regulated during urothelial carcinoma progression. We then used our well characterized urothelial carcinoma cohort to analyze FGF7 transcript and protein expression, and its clinicopathological significance.

MATERIALS AND METHODS

We performed real-time reverse transcriptase-polymerase chain reaction assay to determine the FGF7 transcript level in 30 fresh samples each of upper tract and bladder urothelial carcinoma. Immunohistochemistry evaluated by H-score was used to determine FGF7 protein expression in 340 upper tract and 295 bladder urothelial carcinomas. Transcript and protein expression were correlated with clinicopathological features. We further evaluated the prognostic significance of FGF7 protein expression for disease specific and metastasis-free survival.

RESULTS

An increased FGF7 transcript level was associated with higher pT stage in upper tract and bladder urothelial carcinoma (p = 0.003 and <0.001, respectively). In the upper tract and bladder carcinoma groups FGF7 protein over expression was also significantly associated with advanced pT status (each p <0.001), lymph node metastasis (p = 0.002 and <0.001), high histological grade (p = 0.019 and <0.001), vascular invasion (each p <0.001), perineural invasion (p = 0.002 and 0.021) and frequent mitoses (p = 0.002 and 0.042, respectively). FGF7 over expression predicted dismal disease specific and metastasis-free survival on univariate and multivariate analysis.

CONCLUSIONS

Our study shows that FGF7 over expression is associated with advanced clinical features in patients with upper tract and bladder urothelial carcinoma, justifying its potential prognostic value for urothelial carcinoma.

CCAAT/enhancer-binding protein delta mediates tumor necrosis factor alpha-induced Aurora kinase C transcription and promotes genomic instability

Epidemiologic and clinical research indicates that chronic inflammation increases the risk of certain cancers, possibly through chromosomal instability. However, the mechanism of inflammation-dependent chromosomal instability associated with tumorigenesis is not well characterized. The transcription factor CCAAT/enhancer-binding protein δ (C/EBPδ, CEBPD) is induced by tumor necrosis factor α (TNFα) and expressed in chronically inflamed tissue. In this study, we show that TNFα promotes aneuploidy. Loss of CEBPD attenuated TNFα-induced aneuploidy, and CEBPD caused centromere abnormality. Additionally, TNFα-induced CEBPD expression augmented anchorage-independent growth. We found that TNFα induced expression of aurora kinase C (AURKC) through CEBPD, and that AURKC also causes aneuploidy. Furthermore, high CEBPD expression correlated with AURKC expression in inflamed cervical tissue specimens. These data provide insight into a novel function for CEBPD in inducing genomic instability through the activation of AURKC expression in response to inflammatory signals.

Effect of S-phase kinase-associated protein 2 expression on distant metastasis and survival in nasopharyngeal carcinoma patients

PURPOSE

The S-phase kinase-associated protein 2 (Skp2) oncoprotein is an E3 ubiquitin ligase targeting the p27(Kip1) tumor suppressor for degradation. We evaluated the prognostic utility of Skp2 in nasopharyngeal carcinoma (NPC), with an emphasis on distant metastasis-free (DMF) survival.

METHODS AND MATERIALS

Immunohistochemical expression of Skp2 was assessed by H-score for 233 NPC patients without initial distant metastasis and correlated with the clinicopathologic features, therapeutic modalities, locoregional control rate, DMF survival, and overall survival (OS). No selection bias in essential parameters was shown between these and another 113 control patients.

RESULTS

Skp2 was detectable in most patients (95%) but displayed a wide range of expression. Despite no correlation between Skp2 and any clinicopathologic factor, greater Skp2 expression (H-score >80) significantly portended inferior DMF survival (p = 0.01) and OS (p = 0.02) when categorically dichotomizing the study cohort. The associations with DMF survival (p = 0.003) and OS (p = 0.003) became even stronger when the H-score was expressed as a continuous variable. In the multivariate model, greater Skp2 expression remained significantly predictive of poorer DMF survival and OS (p = 0.01 for both), along with T stage (p = 0.04 for DMF survival; p = 0.005 for OS), N stage (p = 0.008 for DMF survival; p = 0.02 for OS), and/or age (p = 0.001 for OS). In contrast, T stage (p = 0.01) was the single independent prognosticator of LCR.

CONCLUSIONS

The results of our study have shown that Skp2 expression is frequent in NPC and has a wide range of distribution in H-score. Skp2 overexpression is significantly predictive of DMF survival and OS, independent of the T stage and/or older age. Therefore, Skp2 might represent a useful prognostic adjunct to risk stratify NPC patients for appropriate allocation of adjuvant therapy.

Overexpression of the PSAT1 Gene in Nasopharyngeal Carcinoma Is an Indicator of Poor Prognosis

PURPOSE

Nasopharyngeal carcinoma (NPC) is a common cancer in southern China and Southeast Asia, but risk stratification and treatment outcome in NPC patients remain suboptimal. Our study identified and validated metabolic drivers that are relevant to the pathogenesis of NPC using a published transcriptome. Phosphoserine aminotransferase 1 (PSAT1) is an enzyme that is involved in serine biosynthesis, and its overexpression is associated with colon cancer, non-small cell lung cancer and breast cancer. However, its expression has not been systemically evaluated in patients with NPC.

MATERIALS AND METHODS

We evaluated two public transcriptomes of NPC tissues and benign nasopharyngeal mucosal epithelial tissues that deposited in the NIH Gene Expression Omnibus database under accession number GSE34574 and GSE12452. We also performed immunohistochemical staining and assessment of PSAT1 in a total of 124 NPC patients received radiotherapy and were regularly followed-up until death or loss. The endpoints analyzed were local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-specific survival (DSS), and overall survival (OS).

RESULTS

We retrospectively evaluated 124 patients with NPC and found that high PSAT1 expression was associated with poor prognosis of NPC and indicator of advanced tumor stage. High PSAT1 expression also correlated with an aggressive clinical course, with significantly shorter DSS (HR= 2.856, 95% CI 1.599 to 5.101), DMFS (HR= 3.305, 95% CI 1.720 to 6.347), LRFS (HR= 2.834, 95% CI 1.376 to 5.835), and OS HR= 2.935, 95% CI 1.646-5.234) in multivariate analyses.

CONCLUSIONS

Our study showed that PSAT1 is a potential prognostic biomarker and higher expression of PSAT1 is associated with a poor prognosis in NPC.

Phase 1b study of pegylated arginine deiminase (ADI-PEG 20) plus Pembrolizumab in advanced solid cancers

BACKGROUND

Pegylated arginine deiminase (ADI-PEG 20) is a metabolism-based strategy that depletes arginine, resulting in tumoral stress and cytotoxicity. Preclinically, ADI-PEG 20 modulates T-cell activity and enhances the therapeutic efficacy of programmed death-1 (PD-1) inhibition.

METHODS

A phase 1b study, including a dose-escalation cohort and an expansion cohort, was undertaken to explore the effects of ADI-PEG 20 in combination with pembrolizumab, an anti-PD-1 antibody, for safety, pharmacodynamics, and response. CD3 levels and programmed death-ligand 1 (PD-L1) expression were assessed in paired biopsies collected prior to and after ADI-PEG 20 treatment but before pembrolizumab.

RESULTS

Twenty-five patients, nine in the dose-escalation cohort and sixteen in the expansion cohort, were recruited. Treatment was feasible with adverse events consistent with those known for each agent, except for Grade 3/4 neutropenia which was higher than expected, occurring in 10/25 (40%) patients. Mean arginine levels were suppressed for 1-3 weeks, but increased gradually. CD3+ T cells increased in 10/12 (83.3%) subjects following ADI-PEG 20 treatment, including in three partial responders (p = .02). PD-L1 expression was low and increased in 3/10 (30%) of subjects. Partial responses occurred in 6/25 (24%) heavily pretreated patients, in both argininosuccinate synthetase 1 proficient and deficient subjects.

CONCLUSIONS

The immunometabolic combination was safe with the caveat that the incidence of neutropenia might be increased compared with either agent alone. ADI-PEG 20 treatment increased T cell infiltration in the low PD-L1 tumor microenvironment. The recommended phase 2 doses are 36 mg/m2 weekly for ADI-PEG 20 and 200 mg every 3 weeks for pembrolizumab.

Oct4 upregulates osteopontin via Egr1 and is associated with poor outcome in human lung cancer

BACKGROUND

Roles of cancer stem cells and early growth response gene 1 (Egr1) in carcinogenesis have been extensively studied in lung cancer. However, the role of Egr1 in the metastasis of lung cancer remains undetermined, especially in regard to stem cell-related pathways.

METHODS

Egr1, osteopontin (OPN) and Oct4 expression in human lung cancer was determined by performing immunohistochemistry. Immunoblotting, ELISA, luciferase reporter assay, chromatin immunoprecipitation assay and RT-PCR were performed to validate the regulation of Oct4-Egr1-OPN axis. Moreover, the effect of Oct4-Egr1-OPN axis on lung cancer progression was evaluated by cell migration assay and mice study.

RESULTS

We detected Oct4, Egr1, and OPN expression in clinical specimens from 79 lung cancer patients, including 72 adenocarcinomas and 7 squamous cell carcinomas. High expression of Oct4, Egr1, and OPN accounted for 53, 51, and 57% of the patients, respectively. All of the three biomarkers were positively correlated in clinical human lung cancer. Patients with high expression of OPN were significantly associated with shorter disease-free survivals than those with low expression of OPN (p < 0.05). In lung cancer cells, Oct4 transactivated the Egr1 promoter and upregulated Egr1 expression. In a human lung cancer xenograft model, Oct4-overexpressing tumors expressed elevated levels of Egr1. Furthermore, overexpression of Oct4 in lung cancer cells increased the metastatic potential.

CONCLUSIONS

Egr1 exerts a promoting effect on cancer metastasis in Oct4-overexpressing lung cancer. Thus, therapeutic strategies targeting the Oct4/Egr1/OPN axis may be further explored for the treatment of lung cancer, especially when lung cancer is refractory to conventional treatment due to cancer stem cells.