Francisco Mansilla

Emmprin and Survivin Predict Response and Survival following Cisplatin-Containing Chemotherapy in Patients with Advanced Bladder Cancer

Purpose: Cisplatin-containing chemotherapy is the standard of care for patients with locally advanced and metastatic transitional cell carcinoma of the urothelium. The response rate is ∼50% and tumor-derived molecular prognostic markers are desirable for improved estimation of response and survival. Experimental Design: Affymetrix GeneChip expression profiling was carried out using tumor material from 30 patients. A set of genes with an expression highly correlated to survival time after chemotherapy was identified. Two genes were selected for validation by immunohistochemistry in an independent material of 124 patients receiving cisplatin-containing therapy. Results: Fifty-five differentially expressed genes correlated significantly to survival time. Two of the protein products (emmprin and survivin) were validated using immunohistochemistry. Multivariate analysis identified emmprin expression (hazard ratio, 2.23; P < 0.0001) and survivin expression (hazard ratio, 2.46; P < 0.0001) as independent prognostic markers for poor outcome, together with the presence of visceral metastases (hazard ratio, 2.62; P < 0.0001). In the clinical good prognostic group of patients without visceral metastases, both markers showed significant discriminating power as supplemental risk factors (P < 0.0001). Within this group of patients, the subgroups of patients with no positive, one positive, or two positive immunohistochemistry scores (emmprin and survivin) had estimated 5-year survival rates of 44.0%, 21.1%, and 0%, respectively. Response to chemotherapy could also be predicted with an odds ratio of 4.41 (95% confidence interval, 1.91-10.1) and 2.48 (95% confidence interval, 1.1-5.5) for emmprin and survivin, respectively. Conclusions: Emmprin and survivin proteins were identified as strong independent prognostic factors for response and survival after cisplatin-containing chemotherapy in patients with advanced bladder cancer.

Differential expression of DHHC9 in microsatellite stable and instable human colorectal cancer subgroups

Microarray analysis on pooled samples has previously identified ZDHHC9 (DHHC9) to be upregulated in colon adenocarcinoma compared to normal colon mucosa. Analyses of 168 samples from proximal and distal adenocarcinomas using U133plus2.0 microarrays validated these findings, showing a significant two-fold (log 2) upregulation of DHHC9 transcript (P<10−6). The upregulation was more striking in microsatellite stable (MSS), than in microsatellite instable (MSI), tumours. Genes known to interact with DHHC9 as H-Ras or N-Ras did not show expression differences between MSS and MSI. Immunohistochemical analysis was performed on 60 colon adenocarcinomas, previously analysed on microarrays, as well as on tissue microarrays with 40 stage I–IV tumours and 46 tumours from different organ sites. DHHC9 protein was strongly expressed in MSS compared to MSI tumours, readily detectable in premalignant lesions, compared to the rare expression seen in normal mucosa. DHHC9 was specific for tumours of the gastrointestinal tract and localised to the Golgi apparatus, in vitro and in vivo. Overexpression of DHHC9 decreased the proliferation of SW480 and CaCo2 MSS cell lines significantly. In conclusion, DHHC9 is a gastrointestinal-related protein highly expressed in MSS colon tumours. The palmitoyl transferase activity, modifying N-Ras and H-Ras, suggests DHHC9 as a target for anticancer drug design.

Clusterin expression in normal mucosa and colorectal cancer

The gene Clusterin is a target for cancer therapy in clinical trials. The indication for intervention is up-regulated Clusterin expression. Clusterin has been reported to be deregulated in multiple cancer types, including colorectal cancer (CRC). However, for CRC the studies have disagreed on whether Clusterin is up- or down-regulated by neoplastic cells. In the present study we sought to clarify the expression and distribution of Clusterin mRNAs and proteins in normal and neoplastic colorectal tissue through laser microdissection, variant-specific real time RT-PCR, immunohistochemistry, immunofluorescence, Western blotting, and array-based transcriptional profiling. At the transcript level we demonstrated the expression of two novel Clusterin transcripts in addition to the known transcript, and at the protein level we demonstrated two Clusterin isoforms. Our analysis of normal epithelial cells revealed that among these, Clusterin was only expressed by rare neuroendocrine subtype. Furthermore our analysis showed that in the normal mucosa the majority of the observed Clusterin protein originated from the stromal compartment. In tumors we found that Clusterin was de novo synthesized by non-neuroendocrine cancer cells in ∼25% of cases. Moreover we found that the overall Clusterin level in tumors often appeared to be lower than in normal mucosa due to the stromal compartment often being suppressed in tumors. Although Clusterin in normal neuroendocrine cells showed a basal localization, the localization in cancer cells was often apical and in some cases associated with apical secretion. Collectively our results indicate that Clusterin expression is very complex. We conclude that Clusterin expression is associated with neuroendocrine differentiation in normal epithelia and that the Clusterin observed in neoplastic cells is de novo synthesized. The cases with de novo synthesized Clusterin define a distinct subgroup of CRC that may be of clinical importance as anti-Clusterin therapeutics are now in clinical trials.

Repression of KIAA1199 attenuates Wnt-signalling and decreases the proliferation of colon cancer cells

Background:The KIAA1199 transcript is upregulated in colon adenomas and downregulated upon β-catenin knockdown.Methods:Transcript profiling was performed on >500 colon biopsies, methylation profiling data were compared with transcript data. Immunohistochemistry assessed KIAA1199 protein expression in 270 stage II/III tumours (>3 years follow-up). The effects of stable KIAA1199 knockdown in SW480 cells (three different constructs) were studied using transcriptional profiling, proliferation and protein analysis.Results:The KIAA1199 transcript was strongly upregulated in 95% of adenocarcinomas. Absent expression in normal mucosa correlated with KIAA1199 promotor methylation. Nuclear and cytoplasmic KIAA1199 protein expression was identified in colon adenocarcinomas and other types of cancers. A subpopulation of patients with tumours strongly expressing KIAA1199 in the nucleus showed a better outcome with regard to recurrence as lung or liver metastases. The KIAA1199 knockdown affected the cell cycle and the Wnt-signalling pathway. Reduced cellular proliferation and decreased KI67, phosphorylated retinoblastoma, β-catenin and ASCL2 protein expression supported these findings. Eighteen Wnt-signalling genes differentially expressed upon KIAA1199 knockdown correlated with the KIAA1199 expression profile in clinical specimens.Conclusion:The KIAA1199 knockdown attenuates the effects of the Wnt/β-catenin signalling and it may thus be regarded as a regulatory part of this pathway.

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) overexpression in human colorectal cancer

The alteration of the choline metabolite profile is a well-established characteristic of cancer cells. In colorectal cancer (CRC), phosphatidylcholine is the most prominent phospholipid. In the present study, we report that lysophosphatidylcholine acyltransferase 1 (LPCAT1; NM_024830.3), the enzyme that converts lysophosphatidylcholine into phosphatidylcholine, was highly overexpressed in colorectal adenocarcinomas when compared to normal mucosas. Our microarray transcription profiling study showed a significant (p < 10−8) transcript overexpression in 168 colorectal adenocarcinomas when compared to ten normal mucosas. Immunohistochemical analysis of colon tumors with a polyclonal antibody to LPCAT1 confirmed the upregulation of the LPCAT1 protein. Overexpression of LPCAT1 in COS7 cells localized the protein to the endoplasmic reticulum and the mitochondria and increased LPCAT1 specific activity 38-fold. In cultured cells, overexpressed LPCAT1 enhanced the incorporation of [14C]palmitate into phosphatidylcholine. COS7 cells transfected with LPCAT1 showed no growth rate alteration, in contrast to the colon cancer cell line SW480, which significantly (p < 10−5) increased its growth rate by 17%. We conclude that LPCAT1 may contribute to total choline metabolite accumulation via phosphatidylcholine remodeling, thereby altering the CRC lipid profile, a characteristic of malignancy.

Alternative Splicing of SLC39A14 in Colorectal Cancer is Regulated by the Wnt Pathway

Alternative splicing is a crucial step in the generation of protein diversity and its misregulation is observed in many human cancer types. By analyzing 143 colorectal samples using exon arrays, SLC39A14, a divalent cation transporter, was identified as being aberrantly spliced in tumor samples. SLC39A14 contains two mutually exclusive exons 4A and 4B and the exon 4A/4B ratio was significantly altered in adenomas (p = 3.6 × 10−10) and cancers (p = 9.4 × 10−11), independent of microsatellite stability status. The findings were validated in independent exon array data sets and by quantitative real-time reverse-transcription PCR (qRT-PCR). Aberrant Wnt signaling is a hallmark of colorectal tumorigenesis and is characterized by nuclear β-catenin. Experimental inactivation of Wnt signaling in DLD1 and Ls174T cells by knockdown of β-catenin or overexpression of dominant negative TCFs (TCF1 and TCF4) altered the 4A/4B ratio, indicating that SLC39A14 splicing is regulated by the Wnt pathway. An altered 4A/4B ratio was also observed in gastric and lung cancer where Wnt signaling is also known to be aberrantly activated. The splicing factor SRSF1 and its regulator, the kinase SRPK1, were found to be deregulated upon Wnt inactivation in colorectal carcinoma cells. SRPK1 was also found up-regulated in both adenoma samples (p = 1.5 × 10−5) and cancer samples (p = 5 × 10−4). In silico splicing factor binding analysis predicted SRSF1 to bind predominantly to the cancer associated exon 4B, hence, it was hypothesized that SRPK1 activates SRSF1 through phosphorylation, followed by SRSF1 binding to exon 4B and regulation of SLC39A14 splicing. Indeed, siRNA-mediated knockdown of SRPK1 and SRSF1 in DLD1 and SW480 colorectal cancer cells led to a change in the 4A/4B isoform ratio, supporting a role of these factors in the regulation of SLC39A14 splicing. In conclusion, alternative splicing of SLC39A14 was identified in colorectal tumors and found to be regulated by the Wnt pathway, most likely through regulation of SRPK1 and SRSF1.

Cathepsin E, Maspin, Plk1, and Survivin Are Promising Prognostic Protein Markers for Progression in Non-Muscle Invasive Bladder Cancer

Bladder cancer is a common cancer with particularly high recurrence after transurethral resection. In this study, we investigated the prognostic value of the protein expression of cathepsin E, maspin, polo-like kinase 1 (Plk1), and survivin in patients with stage Ta and T1 urothelial carcinomas. Transcripts from the four genes encoding these proteins were previously included in gene expression signatures for outcome prediction for Ta/T1 bladder cancer. We used three different tissue microarrays with 693 non-muscle invasive urothelial carcinomas from Danish, Swedish, and Spanish patient cohorts with long-term follow-up. Protein expression was measured by immunohistochemistry, and antibody specificity was validated by Western blotting. In the Danish patient cohort, we found the expression of cathepsin E, maspin, Plk1, and survivin to be significantly associated with progression to stage T2 to T4 bladder cancer (for each marker: log-rank test; P < 0.001). Multivariate Cox regression analysis identified cathepsin E (P < 0.001), Plk1 (P = 0.021), maspin (P = 0.001), and survivin (P = 0.001) as independent prognostic markers. Furthermore, maspin, survivin, and cathepsin E expression significantly subgrouped patients already stratified by European Organization for Research and Treatment of Cancer risk scores. Finally, we successfully validated the results in tumors from 410 patients from both Sweden and Spain. We conclude that all four protein markers may have prognostic value in non-muscle invasive bladder cancer for guiding optimal treatment of patients. Additional prospective studies are needed for further validation of the clinical relevance of this marker panel.

TIMP-1 expression in human colorectal cancer is associated with TGF-B1, LOXL2, INHBA1, TNF-AIP6 and TIMP-2 transcript profiles

The balance of activity between the endogenous enzyme inhibitors known as tissue inhibitors of metalloproteinases and their targets, the matrix metalloproteinases, in the extracellular matrix is thought to play an important role in tumour cell invasion. Supporting this notion, we have shown that colorectal cancer patients have increased plasma levels of the tissue inhibitor of metalloproteinases‐1 (TIMP‐1), and that high plasma TIMP‐1 levels are associated with short colorectal cancer patient survival. However, although TIMP‐1 has been extensively studied in cancer, very little is known about how it is regulated. To further elucidate potential mechanisms of regulation of this protein, we did a number of experiments to look at associations between the transcript profile of TIMP‐1 with known matrix metalloproteinases (MMPs) as well as with expression profiles of other genes differentially regulated in human colorectal cancer (CRC) and the other TIMPs 2–4, which have also been associated with the progression of colorectal cancer. Genome‐wide expression profiling of 172 CRC and normal mucosa samples was used to identify transcript changes for the genes under investigation. We found that TIMP‐1 was up‐regulated in CRC samples compared with normal tissue, while TIMP‐2 was down‐regulated. Eight MMPs were up‐regulated in CRC compared with normal tissue. Correlating up‐regulated genes with the TIMP‐1 transcript, we identified 13 that were also up‐regulated in cancerous tissue. Among these were genes associated with the synthesis of extracellullar matrix, genes involved in the TGF‐beta signalling pathway, and genes that are likely transcribed by the tumour cells. These insights add to the complex picture emerging about the regulation of TIMPs in colorectal cancer.

Prediction and diagnosis of bladder cancer recurrence based on urinary content of hTERT, SENP1, PPP1CA, and MCM5 transcripts

BackgroundIdentification of urinary biomarkers for detection of bladder cancer recurrence would be beneficial to minimize the frequency of cystoscopy. Our objective was to determine the usability of urine content of mRNA in the detection and prediction of bladder cancer recurrence.MethodsWe analyzed 123 prospectively cross-sectional collected urine samples from 117 patients with bladder cancer (12 incident cancers and 111 control visits). We used biopsies from cystoscopies as diagnostic criteria for recurrence, and followed the patients for a median time of 28.5 months (range 0-44 months). We measured the levels of hTERT, SENP1, PPP1CA, and MCM5 mRNA in urine by q-RT- PCR.ResultsWe found significant differences in urinary content of hTERT (p < 0.001), SENP1 (p < 0.001), MCM5 (p < 0.001), and PPP1CA (p < 0.001) transcripts, when comparing urine samples from patients with and without tumor present in the bladder. We obtained sensitivity and specificity values for hTERT: 63/73, SENP1: 56/78, MCM5: 63/66, and PPP1CA: 69/63, respectively. Including follow-up data resulted in sensitivity and specificity values for hTERT: 62/84, SENP1:53/84, MCM5: 61/73, and PPP1CA: 65/66. Interestingly, at non-tumor visits the urinary content of especially hTERT (p = 0.0001) and MCM5 (p = 0.02) were significantly associated with subsequent tumour recurrence. Combining the markers with cytology improved the detection. The best combination was hTERT and cytology with a sensitivity of 71% and a specificity of 86% after follow-up. Further prospective validation or registration studies needs to be carried out before clinical use.ConclusionsWe could use the urinary content of hTERT, SENP1, PPP1CA, and MCM5 to detect bladder cancer recurrence. All markers showed a higher sensitivity than cytology. The detection rate improved when including cytology results, but also the combination of hTERT and MCM5 increased the detection rate. Furthermore, hTERT and MCM5 levels predicted subsequent tumor recurrences.

Tumor-specific usage of alternative transcription start sites in colorectal cancer identified by genome-wide exon array analysis

BackgroundApproximately half of all human genes use alternative transcription start sites (TSSs) to control mRNA levels and broaden the transcriptional output in healthy tissues. Aberrant expression patterns promoting carcinogenesis, however, may arise from alternative promoter usage.ResultsBy profiling 108 colorectal samples using exon arrays, we identified nine genes (TCF12, OSBPL1A, TRAK1, ANK3, CHEK1, UGP2, LMO7, ACSL5, and SCIN) showing tumor-specific alternative TSS usage in both adenoma and cancer samples relative to normal mucosa. Analysis of independent exon array data sets corroborated these findings. Additionally, we confirmed the observed patterns for selected mRNAs using quantitative real-time reverse-transcription PCR. Interestingly, for some of the genes, the tumor-specific TSS usage was not restricted to colorectal cancer. A comprehensive survey of the nine genes in lung, bladder, liver, prostate, gastric, and brain cancer revealed significantly altered mRNA isoform ratios for CHEK1, OSBPL1A, and TCF12 in a subset of these cancer types.To identify the mechanism responsible for the shift in alternative TSS usage, we antagonized the Wnt-signaling pathway in DLD1 and Ls174T colorectal cancer cell lines, which remarkably led to a shift in the preferred TSS for both OSBPL1A and TRAK1. This indicated a regulatory role of the Wnt pathway in selecting TSS, possibly also involving TP53 and SOX9, as their transcription binding sites were enriched in the promoters of the tumor preferred isoforms together with their mRNA levels being increased in tumor samples.Finally, to evaluate the prognostic impact of the altered TSS usage, immunohistochemistry was used to show deregulation of the total protein levels of both TCF12 and OSBPL1A, corresponding to the mRNA levels observed. Furthermore, the level of nuclear TCF12 had a significant correlation to progression free survival in a cohort of 248 stage II colorectal cancer samples.ConclusionsAlternative TSS usage in colorectal adenoma and cancer samples has been shown for nine genes, and OSBPL1A and TRAK1 were found to be regulated in vitro by Wnt signaling. TCF12 protein expression was upregulated in cancer samples and correlated with progression free survival.