Aberrant trophoblastic differentiation in human cancer: An emerging novel therapeutic target (Review)

Various types of human cancer may develop aberrant trophoblastic differentiation, including histological changes and altered expression of β‑human chorionic gonadotropin (β‑hCG). Aberrant trophoblastic differentiation in epithelial cancer is usually associated with poor differentiation, tumor metastasis, unfavorable prognosis and treatment resistance. Since β‑hCG‑targeting vaccines have failed in an early phase II trial, it is crucial to obtain a better understanding of the molecular pathogenesis of trophoblastic differentiation in human cancer. The present review summarizes the clinical and translational research on this topic with the aim of accelerating the development of an effective targeted therapy. Ectopic expression of β‑hCG promotes proliferation, migration, invasion, vasculogenesis and epithelial‑mesenchymal transition (EMT) in vitro, and enhances metastatic and tumorigenic capabilities in vivo. Signaling cascades modulated by β‑hCG include the TGF‑β receptor pathway, EMT‑related pathways, the c‑MET receptor tyrosine kinase and mitogen‑activated protein kinase/ERK pathways, and the SMAD2/4 pathway. Taken together, these findings indicated that TGF‑β receptors, c‑MET and ERK1/2 are potential therapeutic targets. Nevertheless, further investigation on the molecular basis of aberrant trophoblastic differentiation is mandatory to improve the design of precision therapy for this aggressive type of human cancer.

Clinical implications of PNA‑sequencing as a complementary test for EGFR mutation analysis in human lung cancer

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the first-line regimen for the treatment of non-small cell lung cancer (NSCLC) patients with EGFR mutations. However, false-negative results are occasionally observed, even with FDA-approved molecular tests. Such examples in have been reported in our pilot study showing a slightly upward-shifted amplification curve using commercial reverse transcription-quantitative (RT-q)PCR. Verification using peptide nucleic acid (PNA) clamping-sequencing, which has a sensitivity of ~0.1%, may allow better prediction of which patients will benefit from EGFR-TKI therapy. To confirm this hypothesis, samples were prospectively collected from 1,783 lung cancer cases diagnosed in National Cheng Kung University Hospital between 2012-2018. An independent lung cancer cohort of 1,944 cases was also recruited from other hospitals. The clinical significance of mutant-enriched PCR with PNA-sequencing was analyzed and patient outcomes were followed. A total of 17 of 34 cases (50%) were found to harbor EGFR mutations by PNA-sequencing. A total of 22 cases were discovered in the independent lung cancer cohort, and 14 of these (63.6%) cases had EGFR mutations. TKIs were administered to 14 of the 17 mutation-positive patients, and a partial response was observed in 4 cases and stable disease in 10 cases. Patients with EGFR mutations receiving a TKI regimen had a longer overall survival (OS) (median: 40.0 vs. 10.0 months) compared with those without treatment. The difference in OS was not significant. Based on the results of the present study, combining RT-qPCR with PNA-sequencing may be a practical supplementary technology in a clinical molecular laboratory for a subset of lung cancer patients in selection of EGFR TKI therapy.

Clinicopathologic Analysis of Micropapillary Urothelial Carcinoma of the Upper Urinary Tract: Implications for HER2-Targeted Therapy

Introduction/Background To determine the clinical significance of micropapillary urothelial carcinoma (MPUC) of the upper urinary tract (UTUC) and a potential therapeutic strategy. Patients and Methods A retrospective cohort study was conducted to examine the incidence of micropapillary UTUC from 2010 to 2018 and its clinicopathological characteristics. Clinical outcomes and cancer-specific survival (CSS) were compared between MPUC and conventional UTUC matched by stage within a 6-month variation of receiving surgery. Results A total of 24 MPUC cases were identified out of 901 cases (2.7%) of urothelial carcinoma (UC) of the renal pelvis and ureter. MPUC was significantly smaller (<3 cm) and associated with nodal metastasis compared with conventional UTUC (P = .017 & 0.021, respectively); however, no significant difference was observed for lymphovascular invasion, distant metastasis, or CSS (P > 0.50, respectively) compared with match controls. Six MPUC patients (25%) developed metastasis to the liver, lymph nodes, and lung during follow-up. Patients with HER2-positive MPUC (3 of 4) had a significantly higher risk of metastasis compared with HER2-negative MPUC (3 of 20; P = 0.035). Conclusions MPUC is an aggressive variant of UTUC and usually presents as a small locally advanced disease. HER2 immunohistochemistry may identify the subset of patients with micropapillary UTUC that are candidates for targeted therapy.

The B56γ3-containing protein phosphatase 2A attenuates p70S6K-mediated negative feedback loop to enhance AKT-facilitated epithelial-mesenchymal transition in colorectal cancer

BACKGROUND

Protein phosphatase 2A (PP2A) is one of the major protein phosphatases in eukaryotic cells and is essential for cellular homeostasis. PP2A is a heterotrimer comprising the dimeric AC core enzyme and a highly variable regulatory B subunit. Distinct B subunits help the core enzyme gain full activity toward specific substrates and contribute to diverse cellular roles of PP2A. PP2A has been thought to play a tumor suppressor and the B56γ3 regulatory subunit was shown to play a key tumor suppressor regulatory subunit of PP2A. Nevertheless, we uncovered a molecular mechanism of how B56γ3 may act as an oncogene in colorectal cancer (CRC).

METHODS

Polyclonal pools of CRC cells with stable B56γ3 overexpression or knockdown were generated by retroviral or lentiviral infection and subsequent drug selection. Co-immunoprecipitation(co-IP) and in vitro pull-down analysis were applied to analyze the protein-protein interaction. Transwell migration and invasion assays were applied to investigate the role of B56γ3 in affecting motility and invasive capability of CRC cells. The sensitivity of CRC cells to 5-fluorouracil (5-FU) was analyzed using the PrestoBlue reagent assay for cell viability. Immunohistochemistry (IHC) was applied to investigate the expression levels of phospho-AKT and B56γ3 in paired tumor and normal tissue specimens of CRC. DataSets of TCGA and GEO were analyzed to investigate the correlation of B56γ3 expression with overall survival rates of CRC patients.

RESULTS

We showed that B56γ3 promoted epithelial-mesenchymal transition (EMT) and reduced the sensitivity of CRC cells to 5-FU through upregulating AKT activity. Mechanistically, B56γ3 upregulates AKT activity by targeting PP2A to attenuate the p70S6K-mediated negative feedback loop regulation on PI3K/AKT activation. B56γ3 was highly expressed and positively correlated with the level of phospho-AKT in tumor tissues of CRC. Moreover, high B56γ3 expression is associated with poor prognosis of a subset of patients with CRC.

CONCLUSIONS

Our finding reveals that the B56γ3 regulatory subunit-containing PP2A plays an oncogenic role in CRC cells by sustaining AKT activation through suppressing p70S6K activity and suggests that the interaction between B56γ3 and p70S6K may serve as a therapeutic target for CRC. Video Abstract.

Dual role of sprouty2 as an inhibitor of RAS/ERK-driven proliferation and a promoter of cancer invasion in KRAS wild-type colorectal cancer

Sprouty2 (SPRY2) is known to inhibit the RAS/MAPK/ERK pathway, and is a potential study target for cancer. The effect of SPRY2 in colorectal cancer (CRC) and whether it is influenced by KRAS mutation are not known. We manipulated SPRY2 gene expression and used an activating KRAS-mutant plasmid to determine its effect on CRC cell function in vitro and/or in vivo. We performed SPRY2 immunohistochemical staining in 143 CRC specimens and analyzed the staining results with various clinicopathological characteristics in relation to KRAS mutation status. SPRY2 knockdown in Caco-2 cells carrying the wild-type (WT) KRAS gene upregulated phosphorylated ERK (p-ERK) levels and increased cell proliferation in vitro, but inhibited cell invasion. However, SPRY2 knockdown in SW480 cells (activating KRAS mutant) or Caco-2 cells transfected with KRAS-mutant plasmid did not significantly alter p-ERK levels, cell proliferation, or invasion. The xenografts of SPRY2-knockdown Caco-2 cells were larger with less deep muscle invasion than those of control cells. The clinical cohort study revealed a positive association of SPRY2 protein expression with pT status, lymphovascular invasion, and perineural invasion in KRAS-WT CRCs. However, the associations were not observed in KRAS-mutant CRCs. Interestingly, high SPRY2 expression was related to shorter cancer-specific survival in both KRAS-WT and KRAS-mutant CRC patients. Our study demonstrated the dual role of SPRY2 as an inhibitor of RAS/ERK-driven proliferation and as a promoter of cancer invasion in KRAS-WT CRC. SPRY2 may promote the invasion and progression of KRAS-WT CRC, and might also enhance KRAS-mutant CRC progression through pathways other than invasion.

High concordance rate of capillary electrophoresis workflow for microsatellite instability analysis and mismatch repair (MMR) immunostaining in colorectal carcinoma

Microsatellite instability (MSI) is the primary predictive biomarker for therapeutic efficacies of cancer immunotherapies. Establishment of the MSI detection methods with high sensitivity and accessibility is important. Because MSI is mainly caused by defects in DNA mismatch repair (MMR), immunohistochemical (IHC) staining for the MMR proteins has been widely employed to predict the responses to immunotherapies. Thus, due to the high sensitivity of PCR, the MSI-PCR analysis has also been recommended as the primary approach as MMR IHC. This study aimed to develop a sensitive and convenient platform for daily MSI-PCR services. The routine workflow used a non-labeling QIAxcel capillary electrophoresis system which did not need the fluorescence labeling of the DNA products or usage of a multi-color fluorescence reader. Furthermore, the 15 and 1000 bp size alignment markers were used to precisely detect the size of the DNA product. A cohort of 336 CRC cases was examined by MSI-PCR on the five mononucleotide MSI markers recommended by ESMO. The PCR products were analyzed in the screening gels, followed by high-resolution gel electrophoresis for confirmation if needed. In the MSI-PCR tests, 90.1% (303/336) cases showed clear major shift patterns in the screening gels, and only 33 cases had to be re-examined using the high-resolution gels. The cohort was also analyzed by MMR IHC is, which revealed 98.5% (331/336) concordance with MSI-PCR. In the five discordant cases, 4 (3 MSI-L and 1 MSS) showed MSH6 loss. Besides, one case exhibited MSI-H but no loss in the MMR IHC. Further NGS analysis, in this case, found that missense and frameshift mutations in the PMS2 and MSH6 genes occurred, respectively. In conclusion, the non-labeling MSI-PCR capillary electrophoresis revealed high concordance with the MMR IHC analysis and is cost- and time-effective. Therefore, it shall be highly applicable in clinical laboratories.

Enhancing diagnosis of T-cell lymphoma using non-recombined T-cell receptor sequences

Clonality assessment, which can detect neoplastic T cells by identifying the uniquely recombined T-cell receptor (TCR) genes, provides important support in the diagnosis of T-cell lymphoma (TCL). BIOMED-2 is the gold standard clonality assay and has proven to be effective in European TCL patients. However, we failed to prove its sensitivity in Taiwanese TCL patients, especially based on the TCRβ gene. To explore potential impact of genetic background in the BIOMED-2 test, we analyzed TCRβ sequences of 21 healthy individuals and two TCL patients. This analysis suggests that genetic variations in the BIOMED-2 primer sites could not explain the difference in sensitivity. The BIOMED-2 test results of the two TCL patients were positive and negative, respectively. Interestingly, a higher percentage (>81%) of non-recombined TCRβ sequences was observed in the test-negative patient than those of the test-positive patient and all healthy individuals (13~66%). The result suggests a new TCR target for enhancing TCL diagnosis. To further explore the hypothesis, we proposed a cost-effective digital PCR assay that quantifies the relative abundance of non-recombined TCRβ sequences containing a J2-2P~J2-3 segment. With the digital PCR assay, bone marrow specimens from TCL patients (n=9) showed a positive outcome (i.e., the relative abundance of the J2-2P~J2-3 sequences ≧5%), whereas non-TCL patients (n=6) gave a negative result. As five of nine TCL patients had a negative BIOMED-2 test result, the J2-2P~J2-3 sequences may improve TCL detection. This is the first report showing the capability of characterizing non-recombined TCR sequences as a supplementary strategy for the BIOMED-2 clonality test.

The significance of SMARCB1 in the pathogenesis of renal cell carcinoma with rhabdoid features

BACKGROUND

Renal cell carcinoma with rhabdoid features (RCC-RF) is an aggressive histologic variant in the adults and is usually unresponsive to standard chemotherapy.

METHODS

Expression of SMARCB1/INI1 was examined in primary RCC-RF (n = 5). Stable INI1 with/without prostaglandin E2 receptor 1 (EP1) knockdown cell lines were created in the ACHN and 786-O RCC cell lines and measured for epidermal growth factor receptor (EGFR)-related signaling pathways. Chemosensitivity to targeted drugs in vitro was tested after knocking down of INI1 in both cell lines. The outcome of co-targeting of INI1 and EP1 in RCC was examined using a tumorigenicity assay.

RESULTS

Expression of INI1 was markedly reduced at both transcriptional and translational levels in primary RCC-RF. Immunohistochemical expression of INI1 protein was lost in the nuclei of rhabdoid cells compared with conventional RCC (n = 8). Using two cell lines with different genetic background, we showed that knocking down of INI1 activates the EGFR signaling with up-regulated AKT and ERK pathways and sensitizes cancer cells to Erlotinib treatment in vitro. However, cell-line dependent effects were also demonstrated with reference to impact of INI1 or EP1 on cell growth, migration and response to Gefitinib or Everolimus treatment in vitro.

CONCLUSION

Inactivation of INI1 may play a role in the pathogenesis of RCC-RF. Erlotinib is recommended in the management of patients with INI1-related RCC.

A Case Report of Posttransplant Lymphoproliferative Disorder After AstraZeneca Coronavirus Disease 2019 Vaccine in a Heart Transplant Recipient

We report a case of a heart transplant recipient who presented with a rapidly growing Epstein-Barr virus (EBV)–positive, diffuse large B-cell lymphoma 7 days after receiving the first dose of the ChAdOx1 nCoV-19 vaccine. Because of the atypical radiologic presentation, the initial tentative diagnosis was a mediastinal abscess. This observation indicates a potential risk of EBV reactivation after coronavirus disease 2019 (COVID-19) vaccination, which might lead to or aggravate the presentation of posttransplant lymphoproliferative disorder in transplantation patients. Transplant surgeons should be aware of the potential immunomodulatory effects of the COVID-19 vaccination.

Development of a novel ALK rearrangement screening test for non-small cell lung cancers

Approximately 5–7% of non–small cell lung cancer (NSCLC) cases harbor an anaplastic lymphoma kinase (ALK) fusion gene and may benefit from ALK inhibitor therapy. To detect ALK fusion genes, we developed a novel test using reverse transcription polymerase chain reaction (RT-PCR) for the ALK kinase domain (KD). Since ALK expression is mostly silenced in the adult with the exception of neuronal tissue, the normal lung tissue, mesothelial lining, and inflammatory cells are devoid of ALK transcript, making ALK KD RT-PCR an ideal surrogate test for ALK fusion transcripts in lung or pleural effusion. The test was designed with a short PCR product (197 bp) to work for both malignant pleural effusion (MPE) and formalin-fixed, paraffin-embedded (FFPE) NSCLC samples. Using ALK IHC as a reference, the sensitivity of the test was 100% for both MPE and FFPE. The specificity was 97.6% for MPE and 97.4% for FFPE. Two false positive cases were found. One was a metastatic brain lesion which should be avoided in the future due to intrinsic ALK expression in the neuronal tissue. The other one resulted from ALK gene amplification. Due to potential false positivity, subsequent confirmation tests such as fluorescence in situ hybridization or multiplex PCR would be preferable. Nevertheless, the test is simple and inexpensive with no false negativity, making it a desirable screening test. It also offers an advantage over multiplex RT-PCR with the capability to detect novel ALK fusions. Indeed through the screening test, we found a novel ALK fusion partner (sperm antigen with calponin homology and coiled-coil domains 1 like gene, SPECC1L) with increased sensitivity to crizotinib in vitro. In summary, a novel RNA-based ALK KD analysis was developed for ALK rearrangement screening in MPE and FFPE specimens of NSCLC. This simple inexpensive test can be implemented as routine diagnostics.

Urothelial carcinoma with trophoblastic differentiation: Reappraisal of the clinical implication and immunohistochemically features

PURPOSE

To investigate the clinical implications of identifying urothelial carcinoma (UC) with trophoblastic differentiation (UCTD).

MATERIALS AND METHODS

A prospective cohort study was performed from 2010 to 2016 to examine the incidence of UCTD in urinary tract cancer and association with clinicopathological indicators and patient outcome.

RESULTS

UCTD was detected in 47 of 859 (5.5%) cases of UC of the bladder and 65 of 635 (10.2%) cases in the upper urinary tract. UCTD of the bladder was significantly associated with non-papillary, multiple, larger size ( > 3 cm), muscle invasion, and nodal metastasis (P ≤ 0.0001, respectively). A higher risk of recurrence (P = 0.005), progression (P < 0.0001), and patient death (P < 0.0001) was observed for UCTD than those with traditional, high-grade UC of the bladder. Among four patterns of expression, focal expression of β-human chorionic gonadotropin was frequently detected in papillary tumor (P < 0.005) and UCs of smaller than 3 cm (P = 0.03). Significant indicators in predicting poor disease-specific overall survival in multivariate statistical model were tumor staging (P = 0.001), followed by non-focal β-hCG expression (P = 0.049).

CONCLUSION

UCTD is more often identified in the upper urinary tract than in the bladder. UCTD of the bladder was significantly associated with higher risk of recurrence, progression, and patient death. Expression of β-hCG in non-focal patterns predicts a worse prognosis for patients with UCTD and deserves an individualized treatment planning.

Seminal Vesicle Schwannoma: Transrectal and Intraoperative Sonographic Findings

Schwannomas, namely neurilemmomas, are benign nerve sheath tumors and comprise the myelin sheaths around the peripheral nerves. Schwannomas commonly occur in the head and neck, or extremities, less found in the mediastinum and retroperitoneum, and rarely in the pelvis. We report a 40-year-old male presenting with an 18-month history of nocturia and urinary frequency. Transrectal ultrasound revealed a well-defined, 2.81 cm × 3.77 cm in size, homogeneous, hypoechoic mass in the tail of the left seminal vesicle, compatible with the finding of a well-demarcated mass at the left seminal vesicle with homogeneous contrast enhancement on computed tomography. He underwent laparoscopic excision of the mass via da Vinci robotic surgical system. Intraoperative sonography showed that the mass exhibited the majority of hypoechoic density with some hyperechoic spots inside. Pathology reveals schwannoma. Both of erectile and ejaculatory functions were claimed postoperatively. Our case report highlights the potential of either intraoperative or preoperative sonography in the assessment of the seminal vesicle schwannoma.

Clinicopathological features of mismatch repair protein expression patterns in colorectal cancer

Microsatellite instability (MSI) is reflective of a deficient mismatch repair (dMMR) system, which is mostly associated with the methylation of mismatch repair (MMR) genes and BRAF mutations in sporadic colorectal cancers (CRCs). We performed a retrospective study to analyze the clinicopathological features of dMMR CRCs and their association with the BRAF V600E mutation. The incidence of dMMR CRCs in our cohort was 7.4 % (118/1603). Immunohistochemistry (IHC) revealed four common dMMR IHC patterns in 116 dMMR CRCs from 110 patients. dMMR type 1 (MLH1-/PMS2-) CRCs were the most frequent pattern, usually showing typical proximal location and MSI histology. The BRAF V600E mutation was almost exclusively observed in dMMR type 1 (32 of 72) and dMMR type 2 (PMS- only, 7 of 18) CRCs (p = 0.001). Patients with dMMR type 3 (MSH2-/MSH6-) CRCs were usually diagnosed at younger ages (p < 0.001) and had the strongest family history of Lynch syndrome-associated tumors (p = 0.002). dMMR type 3 CRCs frequently presented at advanced stages (p = 0.005) with perineural invasion (p = 0.021). We also found a significant positive association of dMMR type 1 and type 3 with advanced stages of CRC, whereas dMMR types 2 and 4 (MSH6- only) were usually diagnosed at early stages of CRC (p < 0.001). In conclusion, BRAF V600E mutations almost exclusively occurred in dMMR type 1 and 2 CRCs. Patterns of MMR protein expression display distinct associations with tumor staging and age at diagnosis.

Five Technologies for Detecting the EGFR T790M Mutation in the Circulating Cell-Free DNA of Patients With Non-small Cell Lung Cancer: A Comparison

Third-generation tyrosine kinase inhibitors (TKIs) were developed to overcome T790M-mediated resistance to earlier generations of epidermal growth factor receptor (EGFR)-targeted TKIs. We compared four well-established and one in-house method for the analysis of the EGFR T790M mutation in plasma cell-free DNA (cfDNA), in hope to find a better way to select non-small cell lung cancer (NSCLC) patients appropriate for 3rd-generation TKI therapy. For sensitivity levels of each method, plasmid DNA with EGFR T790M mutations was serially diluted with cfDNA from healthy controls with wild type EGFR. The clinical performance was analyzed in a clinical cohort of EGFR mutation-positive NSCLC patients with acquired EGFR TKI resistance (n = 40). All methods except the therascreen kit (Qiagen) had a sensitivity level of 10 copies of T790M plasmid DNA in the spiked specimen. The detection rates of the EGFR T790M mutation in plasma cfDNA from the clinical cohort were 42.5, 35, 32.5, 22.5, and 17.5% for the in-house ARMS method, Bio-Rad droplet digital PCR, PANAMutyper, Therascreen EGFR Plasma RGQ PCR Kit and Cobas EGFR Mutation kit (with suboptimal template amounts), respectively. Osimertinib was given to 17 of 20 patients with EGFR T790M mutations. The best treatment responses, based on the RECIST criteria, included 6 partial responses (PR) and 7 stable diseases (SD). The PANAMutyper and the Bio-Rad droplet digital PCR were comparable, the Cobas EGFR Mutation kit required significantly more template for testing. The best combination would be the in-house ARMS method plus the PANAMutyper or Bio-Rad droplet digital PCR, which would have a detection rate of 50% (20/40) and a disease control rate of 76% (13/17).

MiR-338-5p promotes metastasis of colorectal cancer by inhibition of phosphatidylinositol 3-kinase, catalytic subunit type 3-mediated autophagy pathway

Background

In our preliminary screening, expression of miR-338-5p was found to be higher in primary colorectal cancer (CRC) with metastasis. The autophagy related gene- phosphatidylinositol 3-kinase, catalytic subunit type 3 (PIK3C3) appeared to be targeted by miR-338-5p. Here, we provide solid evidence in support of PIK3C3 involved in miR-338-5p related metastasis of CRC in vitro and in vivo.

Methods

The potential clinical relevance of miR-338-5p and its target gene was analysed on benign colorectal polyps and primary CRCs by QPCR. Mouse spleen xenograft experiment was performed to examine the importance of miR-338-5p for metastasis.

Findings

PIK3C3 was one of target genes of miR-338-5p. In primary CRCs, expression of miR-338-5p is positively related to tumour staging, distant metastasis and poor patient survival. Patients with higher ratios of miR-338-5p/PIK3C3 also had significantly poor overall survival, supporting their significance in the progression of CRC. Over-expression of miR-338-5p promotes CRC metastasis to the liver and lung in vivo, in which PIK3C3 was down-regulated in the metastatic tumours. In contrast, overexpression of PIK3C3 in miR-338-5p stable cells inhibited the growth of metastatic tumours. Both migration and invasion of CRC in vitro induced by miR-338-5p are mediated by suppression of PIK3C3. Using forward and reverse approaches, autophagy was proved to involve in CRC migration and invasion induced by miR-338-5p.

Interpretation

MiR-338-5p induces migration, invasion and metastasis of CRC in part through PIK3C3-related autophagy pathway. The miR-338-5p/PIK3C3 ratio may become a prognostic biomarker for CRC patients.

Fund

NCKU Hospital, Taiwan, Ministry of Science and Technology, Taiwan.

An effective and accurate identification system of Mycobacterium tuberculosis using convolution neural networks

Tuberculosis (TB) remains the leading cause of morbidity and mortality from infectious disease in developing countries. The sputum smear microscopy remains the primary diagnostic laboratory test. However, microscopic examination is always time-consuming and tedious. Therefore, an effective computer-aided image identification system is needed to provide timely assistance in diagnosis. The current identification system usually suffers from complex color variations of the images, resulting in plentiful of false object detection. To overcome the dilemma, we propose a two-stage Mycobacterium tuberculosis identification system, consisting of candidate detection and classification using convolution neural networks (CNNs). The refined Faster region-based CNN was used to distinguish candidates of M. tuberculosis and the actual ones were classified by utilizing CNN-based classifier. We first compared three different CNNs, including ensemble CNN, single-member CNN, and deep CNN. The experimental results showed that both ensemble and deep CNNs were on par with similar identification performance when analyzing more than 19,000 images. A much better recall value was achieved by using our proposed system in comparison with conventional pixel-based support vector machine method for M. tuberculosis bacilli detection.

Progesterone receptor membrane component 1 as a potential prognostic biomarker for hepatocellular carcinoma

AIM

To investigate the clinicopathological significance of progesterone receptor membrane component 1 (PGRMC1) and PGRMC2 in hepatocellular carcinoma (HCC).

METHODS

We performed immunohistochemical staining to evaluate the estrogen receptor (ER), progesterone receptor (PR), PGRMC1, and PGRMC2 in a clinical cohort consisting of 89 paired HCC and non-tumor liver samples. We also analyzed HCC data (n = 373) from The Cancer Genome Atlas (TCGA). We correlated the expression status of PGRMC1 and PGRMC2 with clinicopathological indicators and the clinical outcomes of the HCC patients. We knocked down or overexpressed PGRMC1 in HCC cell lines to evaluate its biological significance in HCC cell proliferation, differentiation, migration, and invasion.

RESULTS

We found that few HCC cases expressed ER (5.6%) and PR (4.5%). In contrast, most HCC cases expressed PGRMC1 (89.9%) and PGRMC2 (100%). PGRMC1 and PGRMC2 exhibited significantly lower expression in tumor tissue than in non-tumor tissue (P < 0.001). Lower PGRMC1 expression in HCC was significantly associated with higher serum alpha-fetoprotein expression (P = 0.004), poorer tumor differentiation (P = 0.045) and liver capsule penetration (P = 0.038). Low PGRMC1 expression was an independent predictor for worse disease-free survival (P = 0.002, HR = 2.384, CI: 1.377-4.128) in our cases, as well as in the TCGA cohort (P < 0.001, HR = 2.857, CI: 1.781-4.584). The expression of PGRMC2 did not relate to patient outcome. PGRMC1 knockdown promoted a poorly differentiated phenotype and proliferation of HCC cells in vitro, while PGRMC1 overexpression caused the opposite effects.

CONCLUSION

PGRMC1 is a non-classical hormonal receptor that negatively regulates hepatocarcinogenesis. PGRMC1 down-regulation is associated with progression of HCC and is a poor prognostic indicator.

Serrated adenocarcinoma morphology in colorectal mucinous adenocarcinoma is associated with improved patient survival

Colorectal mucinous adenocarcinoma (MAC) and serrated adenocarcinoma (SAC) share many characteristics, including right-side colon location, frequent mucin production, and various molecular features. This study examined the frequency of SAC morphology in MACs. We assessed the correlation of SAC morphology with clinicopathological parameters, molecular characteristics, and patient prognosis. Eighty-eight colorectal MACs were collected and reviewed for SAC morphology according to Makinen's criteria. We sequenced KRAS and BRAF, assessed CpG island methylator phenotype (CIMP) frequency, and analyzed DNA mismatch repair enzyme levels using immunohistochemistry in tumor samples. SAC morphology was observed in 38% of MACs, and was associated with proximal location (P=0.001), BRAF mutation (P=0.042), CIMP-positive status (P=0.023), and contiguous traditional serrated adenoma (P=0.019). Multivariate analysis revealed that MACs without both SAC morphology and CIMP-positive status exhibited 3.955 times greater risk of cancer relapse than MACs having both characteristics or either one (P=0.035). Our results show that two MAC groups with distinct features can be identified using Makinen's criteria, and suggest a favorable prognostic role for the serrated neoplastic pathway in colorectal MAC.

Whether CD44 is an applicable marker for glioma stem cells

Glioblastoma multiforme (GBM) is one of the most malignant and aggressive brain tumors with great amount of hyaluronan (HA) secretion and CD44 overexpression (HA receptor). CD44 has been suggested as a cancer stem cells (CSCs) marker. However, several clinical studies have indicated that CD44low glioma cell exhibit CSCs traits. Additionally, our previous study indicated that more CD44 expression was associated with a better prognosis in GBM patients. To determine whether CD44 is an appropriate marker of glioma stem cells (GSCs), we manipulated CD44 expression using intrinsic (CD44 knockdown, CD44kd) and extrinsic (HA supplement, HA+) methods. Our results show that CD44kd suppressed cell proliferation by retarding cell cycle progression from G0/G1 to S phase. Furthermore, it caused GSCs traits, including lower expression of differentiation marker (glial fibrillary acidic protein, GFAP), a higher level of sphere formation and higher expression of stem cell markers (CD133, nestin and Oct4). The reduction of CD44 expression induced by HA+ was accompanied by an increase in GSCs properties. Interestingly, the presence of HA+ in glioma cells with GSC traits conversely facilitated differentiation. Our data indicated that the CD44 low-expressing cells exhibit more GSCs straits, suggesting that CD44 is not an appropriate marker for GSCs. Furthermore, the preferential expression of CD44 at the invasive rim in rat glioma specimen implies that CD44 may be more important for invasion and migration instead of GSCs marker in glioma.

The role of Lutheran/basal cell adhesion molecule in human bladder carcinogenesis

Background

Lutheran/basal cell adhesion molecule (Lu/BCAM) is a membrane bound glycoprotein. This study was performed to investigate the role and downstream signaling pathway of Lu/BCAM in human bladder tumorigenesis.

Methods

Five human bladder cancer (E6, RT4, TSGH8301, TCCSUP and J82), one stable mouse fibroblast cell line (NIH-Lu) expressing Lu/BCAM transgene and sixty human uroepithelial carcinoma specimens were analyzed by real-time PCR, immunohistochemistry (IHC), immunofluorescence (IFA) staining, Western blotting and promoter luciferase assay for Lu/BCAM, respectively. The tumorigenicity of Lu/BCAM was demonstrated by focus formation, colony-forming ability, tumour formation, cell adhesion and migration.

Results

H-ras^V12 was revealed to up-regulate Lu/BCAM at both transcriptional and translation levels. Lu/BCAM expression was detected on the membrane of primary human bladder cancer cells. Over-expression of Lu/BCAM in NIH-Lu stable cells increased focus number, colony formation and cell adhesion accompanied with F-actin rearrangement and decreased cell migration compared with parental NIH3T3 fibroblasts. In the presence of laminin ligand, Lu/BCAM overexpression further suppressed cell migration accompanied with increased cell adhesion. We further revealed that laminin-Lu/BCAM-induced cell adhesion and F-actin rearrangement were through increased Erk phosphorylation with an increase of RhoA and a decrease of Rac1 activity. Similarly, high Lu/BCAM expression was detected in the tumors of human renal pelvis, ureter and bladder, and was significantly associated with advanced tumor stage (p = 0.02). Patients with high Lu/BCAM expression showed a trend toward larger tumor size (p = 0.07) and lower disease-specific survival (p = 0.08), although not reaching statistical significance.

Conclusion

This is the first report showing that Lu/BCAM, in the presence of its ligand laminin, is oncogenic in human urothelial cancers and may have potential as a novel therapeutic target.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-017-0360-x) contains supplementary material, which is available to authorized users.

EMP1, EMP 2, and EMP3 as novel therapeutic targets in human cancer

The epithelial membrane protein genes 1, 2, and 3 (EMP1, EMP2, and EMP3) belong to the peripheral myelin protein 22-kDa (PMP22) gene family, which consists of at least seven members: PMP22, EMP1, EMP2, EMP3, PERP, brain cell membrane protein 1, and MP20. This review addresses the structural and functional features of EMPs, detailing their tissue distribution and functions in the human body, their expression pattern in a variety of tumors, and highlighting the underlying mechanisms involved in carcinogenesis. The implications in cancer biology, patient prognosis prediction, and potential application in disease therapy are discussed. For example, EMP1 was reported to be a biomarker of gefitinib resistance in lung cancer and contributes to prednisolone resistance in acute lymphoblastic leukemia patients. EMP2 functions as an oncogene in human endometrial and ovarian cancers; however, characteristics of EMP2 in urothelial cancer fulfill the criteria of a suppressor gene. Of particular interest, EMP3 overexpression in breast cancer is significantly related to strong HER-2 expression. Co-expression of HER-2 and EMP3 is the most important indicator of progression-free and metastasis-free survival for patients with urothelial carcinoma of the upper urinary tract. Altogether, discovery of pharmacological inhibitors and/or regulators of EMP protein activity could open novel strategies for enhanced therapy against EMP-mediated human diseases.

Immunohistochemical overexpression of hypoxia-induced factor 1α associated with slow reduction in 18fluoro-2-deoxy-D-glucose uptake for chemoradiotherapy in patients with pharyngeal cancer

BACKGROUND

This study examined genomic factors associated with a reduction in ¹⁸fluoro-2-deoxy-D-glucose (FDG) uptake during positron emission tomography-computed tomography (PET-CT) for definitive chemoradiotherapy (CRT) in patients with pharyngeal cancer.

METHODS

The pretreatment and interim PET-CT images of 25 patients with advanced pharyngeal cancers receiving definitive CRT were prospectively evaluated. The maximum standardized uptake value (SUV_max) of the interim PET-CT and the reduction ratio of the SUV_max (SRR) between the two images were measured. Genomic data from pretreatment incisional biopsy specimens (SLC2A1, CAIX, VEGF, HIF1A, BCL2, Claudin-4, YAP1, MET, MKI67, and EGFR) were analyzed using tissue microarrays. Differences in FDG uptake and SRRs between tumors with low and high gene expression were examined using the Mann-Whitney test. Cox regression analysis was performed to examine the effects of variables on local control.

RESULTS

The SRR of the primary tumors (SRR-P) was 0.59 ± 0.31, whereas the SRR of metastatic lymph nodes (SRR-N) was 0.54 ± 0.32. Overexpression of HIF1A was associated with a high iSUV_max of the primary tumor (P < 0.001) and neck lymph node (P = 0.04) and a low SRR-P (P = 0.02). Multivariate analysis revealed that patients who had tumors with low SRR-P or high HIF1A expression levels showed inferior local control.

CONCLUSION

In patients with pharyngeal cancer requiring CRT, HIF1A overexpression was positively associated with high interim SUV_max or a slow reduction in FDG uptake. Prospective trials are needed to determine whether the local control rate can be stratified using the HIF1A level as a biomarker and SRR-P.

Epidermal Growth Factor Receptor Mutation and Anaplastic Lymphoma Kinase Gene Fusion: Detection in Malignant Pleural Effusion by RNA or PNA Analysis

Analyzing EGFR mutations and detecting ALK gene fusion are indispensable when planning to treat pulmonary adenocarcinoma. Malignant pleural effusion (MPE) is a devastating complication of lung cancer and sometimes the only source for mutation analysis. The percentage of tumor cells in the pleural effusion may be low; therefore, mutant enrichment is required for a successful analysis. The EGFR mutation status in MPE was determined using three methods: (1) PCR sequencing of genomic DNA (direct sequencing), (2) mutant-enriched PCR sequencing of genomic DNA using peptide nucleic acid (PNA-sequencing), and (3) PCR sequencing of cDNA after reverse transcription for cellular RNA (RNA-sequencing). RT-PCR was also used to test cases for ALK gene fusion.

PNA-sequencing and RNA-sequencing had similar analytical sensitivities (< 1%), which indicates similar enrichment capabilities. The clinical sensitivity in 133 cases when detecting the common EGFR exon 19 and exon 21 mutations was 56.4% (75/133) for direct sequencing, 63.2% (84/133) for PNA-sequencing, and 65.4% (87/133) for RNA-sequencing. RT-PCR and sequencing showed 5 cases (3.8%) with ALK gene fusion. All had wild-type EGFR. For EGFR analysis of MPE, RNA-sequencing is at least as sensitive as PNA-sequencing but not limited to specific mutations. Detecting ALK fusion can be incorporated in the same RNA workflow. Therefore, RNA is a better source for comprehensive molecular diagnoses in MPE.

RON Nuclear Translocation under Hypoxia Potentiates Chemoresistance to DNA Double-Strand Break-Inducing Anticancer Drugs

Tumor hypoxia is associated with radioresistance, chemoresistance, and metastasis, which eventually lead to cancer progression and a poor patient prognosis. RON [also known as macrophage-stimulating protein receptor (MST1R)] belongs to the c-MET [also known as hepatocyte growth factor receptor (HGFR)] receptor tyrosine kinase (RTK) superfamily. To identify the interaction partners of RON nuclear translocation in response to hypoxia, the nuclear extract of TSGH8301 bladder cancer cells was immunoprecipitated for tandem mass profiling analysis. Nuclear RON interacted with adenosine triphosphate (ATP)-dependent DNA helicase 2 (Ku70) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to activate nonhomologous end joining (NHEJ) DNA repair. The interaction was time dependent, extending 3 to 24 hours posthypoxia or until the components had been exposed to the chemotherapeutic drugs doxorubicin and epirubicin. Stable knockdown experiments in vitro suggest the importance of RON for the chemoresistance of cancer cells under hypoxia. In addition, the tyrosine kinase domain of nuclear RON is crucial for interaction with Ku70 under hypoxia. J82 cells transfected with RON showed a survival advantage in the presence of epirubicin and hypoxia. This suggests that nuclear RON activates NHEJ repair by interacting with Ku70/DNA-PKcs and inhibiting RON activity to increase cancer cell chemosensitivity. Mol Cancer Ther; 15(2); 276-86. ©2016 AACR.

SH3BGRL3 Protein as a Potential Prognostic Biomarker for Urothelial Carcinoma: A Novel Binding Partner of Epidermal Growth Factor Receptor

PURPOSE

Mass spectrometry-based biomarker discovery has clinical benefit. To identify novel biomarkers for urothelial carcinoma, we performed quantitative proteomics on pooled urine pairs from patients with and without urothelial carcinoma.

EXPERIMENTAL DESIGN

Shot-gun proteomics using liquid chromatography-tandem mass spectrometry and stable isotope dimethyl labeling identified 219 candidate proteins. The potential implication of SH3 domain binding glutamic acid-rich protein like 3 (SH3BGRL3) was examined by immunoblotting of the urine (n = 13) and urothelial tumors (n = 32). Additional immunohistochemistry was performed on bladder cancer array (n = 1145) and correlated with tumor aggressiveness. Then, biologic functions and signaling pathways of SH3BGRL3 were explored using stable cell lines.

RESULTS

The detectable urine SH3BGRL3 in patients with urothelial carcinoma was positively associated with higher histologic grading and muscle invasiveness of urothelial carcinoma. SH3BGRL3 is expressed in 13.9% (159/1145) of bladder cancer cohort and is positively associated with muscle invasion (P = 0.0028). SH3BGRL3 expression is associated with increased risk of progression in patients with nonmuscle-invasive bladder cancer (P = 0.032). SH3BGRL3 expression is significantly associated with a high level of epidermal growth factor receptor (EGFR) in bladder cancer (P < 0.0001). SH3BGRL3 promotes the epithelial-mesenchymal transition, cell migration, and proliferation of urothelial carcinoma in vitro. SH3BGRL3 interacts with phosphor-EGFR at Y1068, Y1086, and Y1173 through Grb2 by its proline-rich motif, and activates the Akt-associated signaling pathway.

CONCLUSIONS

Evaluation of SH3BGRL3 expression status or urine content may identify a subset of patients with bladder cancer who may require more intensive treatment. SH3BGRL3 deserves further investigation as a cotargeting candidate for designing EGFR-based cancer therapies. Clin Cancer Res; 21(24); 5601-11. ©2015 AACR.

Ras induces experimental lung metastasis through up-regulation of RbAp46 to suppress RECK promoter activity

Background

Mutant Ras plays multiple functions in tumorigenesis including tumor formation and metastasis. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), a metastasis inhibitor gene, suppresses matrix metalloproteinase (MMP) activity in the metastatic cascade. Clarifying the relationship between Ras and RECK and understanding the underlying molecular mechanism may lead to the development of better treatment for Ras-related tumors.

Methods

Suppression subtractive hybridization PCR (SSH PCR) was conducted to identify Ha-ras^val12 up-regulated genes in bladder cancer cells. Stable cell lines of human breast cancer (MCF-7-ras) and mouse NIH3T3 fibroblasts (7–4) harboring the inducible Ha-ras^val12 oncogene, which could be induced by isopropylthio-β-D-galactoside (IPTG), were used to clarify the relationship between Ras and the up-regulated genes. Chromatin immunoprecipitation (ChIP) assay, DNA affinity precipitation assay (DAPA) and RECK reporter gene assay were utilized to confirm the complex formation and binding with promoters.

Results

Retinoblastoma binding protein-7 (RbAp46) was identified and confirmed as a Ha-ras^val12 up-regulated gene. RbAp46 could bind with histone deacetylase (HDAC1) and Sp1, followed by binding to RECK promoter at the Sp1 site resulting in repression of RECK expression. High expression of Ras protein accompanied with high RbAp46 and low RECK expression were detected in 75% (3/4) of the clinical bladder cancer tumor tissues compared to the adjacent normal parts. Ras induced RbAp46 expression increases invasion of the bladder cancer T24 cells and MMP-9 activity was increased, which was confirmed by specific lentiviral shRNAs inhibitors against Ras and RbAp46. Similarly, knockdown of RbAp46 expression in the stable NIH3T3 cells “7-4” by shRNA decreased Ras-related lung metastasis using a xenograft nude mice model.

Conclusions

We confirmed that RbAp46 is a Ha-ras^val12 up-regulated gene and binds with HDAC1 and Sp1. Furthermore, RbAp46 binds to the RECK promoter at the Sp1 site via recruitment by Sp1. RECK is subsequently activated, leading to increased MMP9 activity, which may lead to increased metastasis in vivo. Our findings of Ras upregulation of RbAp46 may lead to revealing a novel mechanism of Ras-related tumor cell metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1155-7) contains supplementary material, which is available to authorized users.

Verification of wild-type EGFR status in non-small cell lung carcinomas using a mutant-enriched PCR on selected cases

EGFR genotyping is required for targeted therapy of lung adenocarcinoma. Because a false-negative result might prevent a patient from receiving appropriate targeted therapies, it is desirable to recheck equivocal results of EGFR genotyping. A cohort of 346 lung cancers was tested with a commercial kit for EGFR mutations; nine of the cases had upward real-time amplification curves at late cycles. They were also investigated using mutant-enriched PCR with peptide nucleic acid-locked nucleic acid (PNA-sequencing). Six of the nine equivocal cases harbored EGFR mutations. These cases likely had a small amount of mutant DNA near the detection limit of the commercial kit. Twenty nonequivocal, wild-type cases were reconfirmed using PNA-sequencing. We noticed a College of American Pathologists proficiency test material that showed a suspicious upward curve and eventually proved to have an H773_V774insPH in exon 20, for which a specific primer was not designed in the commercial kit. Further study using cloned DNA fragments showed that the upward curve most likely resulted from cross-reaction between similar, but nonidentical, sequences. It is desirable to keep the number of false-negative results as low as possible, but rechecking all wild-type cases is impractical. The late upward curves we observed helped identify suspicious cases for rechecking. A second method, such as PNA-sequencing, is recommended to verify wild-type cases.

Hypoxia promotes nuclear translocation and transcriptional function in the oncogenic tyrosine kinase RON

Tumor hypoxia drives metastatic progression, drug resistance, and posttreatment relapses, but how cancer cells adapt and evolve in response to hypoxic stress is not well understood. In this study, we address this question with the discovery that the receptor tyrosine kinase RON translocates into the nucleus of hypoxic cancer cells. In response to hypoxia, nuclear RON interacts with the hypoxia-inducible factor HIF-1α in a manner that relies on RON tyrosine kinase activity, binding to the c-JUN promoter and activating it. Mechanistic investigations revealed unexpectedly that nuclear RON played a more important role in activation of the c-JUN promoter than HIF-1α, leading to increased cell proliferation, survival adaptation, in vitro migration, and tumorigenicity under hypoxic conditions. Taken together, our results pointed to a novel function for RON as a transcriptional regulator that promotes the survival of cancer cells subjected to hypoxia. These results suggest novel implications for the use of small-molecule inhibitors or monoclonal antibodies targeting the RON kinase in the prevention or treatment of advanced cancer.

Potential significance of EMP3 in patients with upper urinary tract urothelial carcinoma: crosstalk with ErbB2-PI3K-Akt pathway

PURPOSE

Upper urinary tract (pyelocalyceal cavities and ureter) urothelial carcinoma is a relatively rare neoplastic disease. Although diagnosis and treatment of this tumor variant have improved significantly, accurate risk stratification remains a challenge. To identify the putative oncogene involved in urothelial carcinoma progression we performed bioinformatics guided experimental investigation targeting chromosome 19q13.

MATERIALS AND METHODS

We investigated the effects of EMP3 on cancer cell growth, migration and adhesion in transfection and siRNA experiments in vitro. Crosstalk of integrins or ErbB2 with EMP3 was examined by reverse transcriptase-polymerase chain reaction and immunoblot. The potential involvement of epigenetic alterations of EMP3 in vitro and in vivo was analyzed by methylation specific polymerase chain reaction. To validate clinical relevance we measured EMP3 expression at the mRNA and protein levels in a cohort of 77 patients with upper urinary tract urothelial carcinoma and compared prognostic significance in relation to that of ErbB2 expression.

RESULTS

We noted functional crosstalk between ErbB2 and EMP3 in vitro. EMP3 over expression promoted cancer cell proliferation and migration but suppressed cell adhesion in vitro. EMP3 activated the ErbB2-PI3K-AKT pathway to increase cell growth in vitro. In the clinical cohort Kaplan-Meier survival estimates showed that ErbB2 and EMP3 co-expression was the most important indicator of progression-free and metastasis-free survival in patients with upper urinary tract urothelial carcinoma (log rank test p = 0.018 and 0.04, respectively).

CONCLUSIONS

EMP3 is an important prognostic indicator for selecting patients with upper urinary tract urothelial carcinoma for more intensive therapy. EMP3 is an innovative co-targeting candidate for designing ErbB2 based cancer therapy.

Lin28B is an oncofetal circulating cancer stem cell-like marker associated with recurrence of hepatocellular carcinoma

By using an expressed sequence tag bioinformatic algorithm, we identified that Lin28 homolog B (Lin28B) may have an oncofetal expression pattern which may facilitate detecting cancer cells in adults. It is also reported to be a potential marker for cancer stem cells. Therefore, we sought to verify oncofetal-stemness characters of Lin28B and test its potential as a circulating cancer stem cell-like marker in adult HCC patients. Lin28B mRNA was examined in a panel of fetal tissue, adult tissue and tumors. Lin28B was over-expressed or knocked down in HepG2 cells to evaluate its potential as a stem cell-like marker. RT-qPCR for Lin28B was performed in the peripheral blood mononuclear cells from patients with HCC receiving surgery (n=96) and non-HCC controls (n=60) and analyzed its clinical significance. Lin28B showed an oncofetal expression pattern. Its overexpression could upregulate stemness markers (OCT4, Nanog and SOX2) and enhance tumorsphere formation in vitro. Lin28B knockdown had opposite effects. Circulating Lin28B was detected in peripheral blood mononuclear cells in 3 cases (5%) of non-HCC controls and 32 cases (33.3%) of HCC patients. In HCC patients, circulating Lin28B was associated with high tumor grade (P=0.046), large size (P=0.005), high AJCC stage (P=0.044) and BCLC stage (P=0.017). Circulating Lin28B was significantly associated with decreased recurrence-free survival (P<0.001). Circulating Lin28B separated early stage HCC into 2 recurrence-free survival curves (P=0.003). In multivariate analysis, circulating Lin28B was an independent variable associated with early recurrence (P=0.045) and recurrence in early stage HCC (P=0.006). In conclusion, the oncofetal gene Lin28B is a potential oncofetal cancer-stem-cell-like circulating tumor cell marker that correlates with HCC recurrence after hepatectomy. Circulating Lin28B could refine early AJCC stages. Our finding supports the possible use of a TNMC (C for circulating tumor cells) staging system in HCC.

Epithelial membrane protein 2 is a prognostic indictor for patients with urothelial carcinoma of the upper urinary tract

Upper urinary tract urothelial carcinoma is a relatively uncommon disease and is diagnosed more frequently at advanced stages. The prognosis of these patients mainly has been related to tumor stage and grade. As a result, the definition of prognostic indicators enabling precise patient selection is mandatory for neoadjuvant or adjuvant therapies. The epithelial membrane protein (EMP2) was identified as one of the up-regulated genes by isoflavones. EMP2 overexpression suppressed foci formation, anchorage-independent growth in vitro, and tumorigenicity in severe combined immunodeficiency mice (all P < 0.05). In addition, a cross-talk between EMP2 and integrins αV and β3 was shown in the regulation of cell adhesion and migration. Higher EMP2 expression was associated with a better progression-free survival (P = 0.008) and cancer-related death (P < 0.001). EMP2 was identified as a tumor-suppressor gene in urinary tract urothelial carcinoma and may be an innovative co-targeting candidate for designing integrin-based cancer therapy.

Computed tomography with histological correlation for evaluating tumor regression of rectal carcinoma after preoperative chemoradiation therapy

BACKGROUND/AIMS

Preoperative chemoradiation therapy (CRT) is standard procedure for locally advanced rectal cancer. The correlation of tumor response evaluated using CT according to response evaluation criteria in solid tumors (RECIST) with the histo-logical tumor regression grade (TRG) is not well-documented.

METHODOLOGY

Ninety-one patients with rectal cancer underwent CT examinations before and after preoperative CRT and following surgery. Clinical tumor staging and tumor response assessed according to RECIST were done on paired CT scans. Pathological tumor staging and TRGs were reviewed in resected specimens.Post-CRT CT findings and histological findings were compared. Survival analysis for 73 patients was done.

RESULTS

TRG was positively correlated with the CT-assessed tumor response (r=0.276, p=0.009). Thickened fibrotic areas and muscle disarray caused by fibrosis were more frequently seen in cases of patients over-diagnosed as having residual tumors. The ycT status was positively correlated with ypT status (r=0.44, p<0.001;accuracy=61.5%). Downstaging of cT status was cor-related with a lower TRG (p=0.001).

CONCLUSIONS

Fibrosis emerges after neoadjuvant therapy and is usual-ly accompanied by tumor reduction on CT scans of rec-tal cancer patients following preoperative CRT. There-fore, tumor response assessed using CT according to RECIST may serve as a supplementary tool for preoperative planning other than tumor restaging.

Loss of epithelial membrane protein-2 expression confers an independent prognosticator in nasopharyngeal carcinoma: a cohort study

OBJECTIVE

To evaluate the expression of epithelial membrane protein-2 (EMP2) protein and its clinicopathological associations in patients with nasopharyngeal carcinoma.

DESIGN

Retrospective population-based cohort study.

SETTING

This study was based on a biobank in Chi-Mei Medical Center (Tainan, Taiwan) from 1993 to 2002.

PARTICIPANTS

Biopsies of 124 consecutive nasopharyngeal carcinoma patients without initial distant metastasis and treated with consistent guidelines were assessed. Immunoexpressions of EMP2 were analysed and the outcomes were correlated with clinicopathological features and patient survivals.

PRIMARY AND SECONDARY OUTCOME MEASURES

Immunoexpressions of EMP2 were analyzed and the outcomes were correlated with clinicopathological features and patient survivals.

RESULTS

Loss of EMP2 expression (49.2%) was correlated with advanced primary tumour (p=0.044), nodal status (p=0.045) and the 7th American Joint Committee on Cancer stage (p=0.027). In multivariate analyses, loss of EMP2 expression emerged as an independent prognosticator for worse disease-specific survival (DSS; p=0.015) and local recurrence-free survival (LRFS; p=0.030), along with the American Joint Committee on Cancer stages III-IV (p=0.034, DSS; p=0.023, LRFS).

CONCLUSIONS

Loss of EMP2 expression is common and associated with adverse prognosticators and might confer tumour aggressiveness through hampering its interaction with specific membrane protein(s) and hence the downstream signal transduction pathway(s).

Transcriptional activation of the Axl and PDGFR-α by c-Met through a ras- and Src-independent mechanism in human bladder cancer

BACKGROUND

A cross-talk between different receptor tyrosine kinases (RTKs) plays an important role in the pathogenesis of human cancers.

METHODS

Both NIH-Met5 and T24-Met3 cell lines harboring an inducible human c-Met gene were established. C-Met-related RTKs were screened by RTK microarray analysis. The cross-talk of RTKs was demonstrated by Western blotting and confirmed by small interfering RNA (siRNA) silencing, followed by elucidation of the underlying mechanism. The impact of this cross-talk on biological function was demonstrated by Trans-well migration assay. Finally, the potential clinical importance was examined in a cohort of 65 cases of locally advanced and metastatic bladder cancer patients.

RESULTS

A positive association of Axl or platelet-derived growth factor receptor-alpha (PDGFR-α) with c-Met expression was demonstrated at translational level, and confirmed by specific siRNA knock-down. The transactivation of c-Met on Axl or PDGFR-α in vitro was through a ras- and Src-independent activation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MEK/ERK) pathway. In human bladder cancer, co-expression of these RTKs was associated with poor patient survival (p < 0.05), and overexpression of c-Met/Axl/PDGFR-α or c-Met alone showed the most significant correlation with poor survival (p < 0.01).

CONCLUSIONS

In addition to c-Met, the cross-talk with Axl and/or PDGFR-α also contributes to the progression of human bladder cancer. Evaluation of Axl and PDGFR-α expression status may identify a subset of c-Met-positive bladder cancer patients who may require co-targeting therapy.

Urinary CD14 as a potential biomarker for benign prostatic hyperplasia - discovery by combining MALDI-TOF-based biostatistics and ESI-MS/MS-based stable-isotope labeling

PURPOSE

Quest for specific urinary biomarkers for benign prostatic hyperplasia (BPH).

EXPERIMENTAL DESIGN

Proteomics studies were conducted with urines of the training set to discovering marker candidates that could differentiate BPH from normal subjects by matching results deduced from MALDI-TOF of individual samples and results deduced from nanoLC-ESI-MS/MS-based stable isotope dimethyl labeling of two pooled samples (BPH and normal). Samples were digested before analysis and such an approach takes into account the subject-to-subject variation and differential amount, as well as protein identification. Selected markers were validated by ELISA conducted on the training set and the test set as well as another set of urines collected from prostate cancer patients.

RESULTS

Nine marker candidates were identified from proteomics studies; CD14, prostate-specific antigen and pancreatic α-amylase precursor were further selected for ELISA validation. Urinary CD14 is among the best match with high specificity (>81%) for both training and test sets. In addition, from the study of prostate cancer patients, CD14 also allows the distinction of BPH from cancer with high specificity (84-100%) when combined with urinary prostate-specific antigen.

CONCLUSIONS AND CLINICAL RELEVANCE

Urinary CD14 is suggested to have a high specificity in the diagnosis of BPH in distinction from normal as well as cancer subjects.

High percentage of JAK2 exon 12 mutation in Asian patients with polycythemia vera

We examined the occurrence of JAK2(V617F) and JAK2 exon 12 mutations in a clinical cohort of polycythemia vera (PV) in Taiwan. Of 22 patients with PV, 17 (77%) had the V617F mutation, and all 5 V617F-negative patients (23%) had the exon 12 mutation. We found 3 different exon 12 mutations: 3 N542-E543del, 1 F537-K539delinsL, and 1 novel mutation, I540-E543delinsKK. Patients with V617F showed significantly higher WBC and platelet counts at diagnosis than patients with exon 12 mutations (P = .021 and P = .038, respectively). We report a surprisingly high incidence of exon 12 mutations in Taiwanese patients with PV, a result quite different from reports in the Western literature (P = .001). Our data suggest that exon 12 mutation of JAK2 in patients with PV may have an uneven geographic distribution. A clinical laboratory providing the V617F test alone may risk missing a substantial number of patients with PV in areas with a high incidence of exon 12 mutation.

An unusual function of RON receptor tyrosine kinase as a transcriptional regulator in cooperation with EGFR in human cancer cells

Homodimerization of RON (MST1R), a receptor tyrosine kinase, usually occurs in cells stimulated by a ligand and leads to the downstream activation of signaling pathways. Here we report that bladder cancer cells, in response to physiological stress, use an alternative mechanism for signaling activation. Time-course studies indicated that RON migrated directly from the membrane to the nucleus of bladder cancer cells in response to serum starvation. Biochemical and genetic studies implied that this nuclear internalization was complexed with epidermal growth factor receptor (EGFR) and required the docking of importins. In vivo analysis confirmed that nuclear RON was present in 38.4% (28/73) of primary bladder tumors. Chromatin immunoprecipitation (ChIP) on microarray analysis further revealed that this internalized complex bound to at least 134 target genes known to participate in three stress-responsive networks: p53, stress-activated protein kinase/c-jun N-terminal kinase and phosphatidylinositol 3-kinase/Akt. These findings suggest that RON, in a complex with EGFR, acts as a transcriptional regulator in response to acute disturbances (e.g. serum starvation) imposed on cancer cells. In an attempt to re-establish homeostasis, these cells bypass regular mechanisms required by ligand stimulation and trigger the RON-directed transcriptional response, which confers a survival advantage.

Nucleophosmin in the pathogenesis of arsenic-related bladder carcinogenesis revealed by quantitative proteomics

To investigate the molecular mechanisms of arsenic (As)-associated carcinogenesis, we performed proteomic analysis on E7 immortalized human uroepithelial cells after treatment with As in vitro. Quantitative proteomics was performed using stable isotope dimethyl labeling coupled with two-dimensional liquid chromatography peptide separation and mass spectrometry (MS)/MS analysis. Among 285 proteins, a total of 26 proteins were upregulated (ratio>2.0) and 18 proteins were downregulated (ratio<0.65) by As treatment, which are related to nucleotide binding, lipid metabolism, protein folding, protein biosynthesis, transcription, DNA repair, cell cycle control, and signal transduction. This study reports the potential significance of nucleophosmin (NPM) in the As-related bladder carcinogenesis. NPM was universally expressed in all of uroepithelial cell lines examined, implying that NPM may play a role in human bladder carcinogenesis. Upregulation of NPM tends to be dose- and time-dependent after As treatment. Expression of NPM was associated with cell proliferation, migration and anti-apoptosis. On the contrary, soy isoflavones inhibited the expression of NPM in vitro. The results suggest that NPM may play a role in the As-related bladder carcinogenesis, and soybean-based foods may have potential in the suppression of As/NPM-related tumorigenesis.

Immunohistochemical detection of prostate-specific antigen expression in primary urothelial carcinoma of the urinary bladder

BACKGROUND

Prostate-specific antigen (PSA) is a 33-kDa serine protease that is secreted by prostatic epithelium and non-prostate tissues. Ectopic expression of PSA has also been reported in a variety of non-prostatic epithelial tumors.

PATIENTS AND METHODS

Expression of PSA and its clinical implication were examined in a total of 422 cases of primary urothelial carcinoma of the bladder.

RESULTS

Cytoplasmic reactivity to PSA was observed in 6 cases (1.4%), with the staining being to a low degree in 3 and a high degree in the remaining 3 cases. Expression of PSA was positively related to multiplicity, large tumors (> or = 3 cm) and muscle invasion (> or = pT2) (p = 0.0008, 0.004 and 0.03, respectively). Patients with tumors of low PSA expression had a better survival than those with tumors of high PSA expression (p = 0.03).

CONCLUSION

Focal expression of PSA can occasionally be detected in some large, invasive urothelial cancer cells. This phenotypic change should be considered in the differential diagnosis of poorly differentiated carcinoma of the lower urinary tract.

Delivery of noncarrier naked DNA vaccine into the skin by supersonic flow induces a polarized T helper type 1 immune response to cancer

BACKGROUND

DNA vaccine is a new and powerful approach to generate immunological responses against infectious disease and cancer. The T helper type (Th)1 immune response is usually required for generating effective anti-tumor responses. A microparticulate bombardment system can induce an immune response using very low amounts of DNA. Using nozzle aerodynamics, a low pressure gene gun has been developed to decrease the noise associated with high pressure gene guns. Particles are propelled by supersonic flow through this novel nozzle. To test whether this gun could inoculate a DNA vaccine that stimulates an anti-tumor Th1 immune response, we examined the effect of direct delivery of naked DNA (i.e. without any carrier) on the anti-tumor immune response of mice.

METHODS

The luciferase reporter plasmid DNA was delivered using a low-pressure biolistic device and expressed in C3H/HeN, BALB/c, and C57BL/6 mice.

RESULTS

Plasmid DNA expression was mainly in the epidermis. Noncarrier naked neu DNA vaccine and gold particle-coated neu DNA vaccine (at 1 microg per mouse) had similar anti-tumor effects in C3H mice. However, cytokine profile examination showed the Th1-bias of the response induced by naked DNA vaccine and the Th2-bias of the response induced by coated DNA vaccine.

CONCLUSIONS

A shift in the immune response to favour enhanced tumor rejection can be achieved by skin delivery of naked DNA vaccine.

The prognostic significance of RON and MET receptor coexpression in patients with colorectal cancer

PURPOSE

Although Recepteur d'Origine Nantais (RON), a member of the MET receptor tyrosine kinase family, is overexpressed and constitutively active in some primary tumors and tumor cell lines, its expression pattern and clinical significance in colorectal cancer are not well documented.

METHODS

By using immunohistochemical staining, we examined RON and MET expression in 135 colorectal cancer specimens and investigated the association of the immunoreactivity of both receptors with colorectal cancer clinical parameters and prognosis.

RESULTS

We found moderate to strong expression in 99 cases (73 percent) for RON and 97 cases (72 percent) for MET. Univariate analysis showed that increased immunoreactivity of RON or MET was associated with shorter patient survival and that moderate to strong coexpression of both receptors was associated with a significantly worse prognosis. Multivariate Cox analysis showed that the risk of tumor recurrence for patients with high-RON/high-MET expression was approximately 11 times greater than for patients with low-RON/low-MET expression (P = 0.001). In addition, RON and MET expression levels were positively correlated (P <or= 0.001; tau = 0.306).

CONCLUSIONS

The crosstalk between RON and MET in colorectal cancer seems important. Evaluating the expression patterns of RON and MET was predictive of clinical outcome for patients with colorectal cancer.

Dengue viruses can infect human primary lung epithelia as well as lung carcinoma cells, and can also induce the secretion of IL-6 and RANTES

Dengue viruses (DENV) are herein demonstrated for the first time as being able to infect and replicate in human primary lung epithelium and various lung cancer cell lines. The detection of dengue virus particles and viral negative strand RNA synthesis in the cell, in conjunction with the release of viral progenies in culture supernatants, support the notion that lung cells are susceptible to dengue virus infection. The replication efficiency of DENV in lung cancer cells from high to low is: DEN-2 (dengue virus type-2), DEN-3, DEN-4 and DEN-1. Moreover, the susceptibility of the six lung cancer cell lines to DEN-2 infection is: SW1573>A549>H1435; H23; H520; Bes2B. DEN-2 infection significantly increased the expression levels of IL-6 and RANTES in four of the six lung cancer cell lines, which is consistent with the high expression levels of these molecules in DHF/DSS patients. IL-6 expression induced by DEN-2 infection was NF-kappaB dependent. In summary, our results indicate that lung epithelial cell is a possible target of dengue viruses and IL-6 and RANTES may play pivotal roles in lung related immuno-pathogenesis.

Eps8 facilitates cellular growth and motility of colon cancer cells by increasing the expression and activity of focal adhesion kinase

In an attempt to study the role of Eps8 in human carcinogenesis, we observe that ectopic overexpression of Eps8 in SW480 cells (low Eps8 expression) increases cell proliferation. By contrast, expressing eps8 small interference RNA in SW620 and WiDr cells (high Eps8 expression) reduces their proliferation rate. Interestingly, attenuation of Eps8 decreases Src Pi-Tyr-416, Shc Pi-Tyr-317, and serum-induced FAK Pi-Tyr-397 and Pi-Tyr-861. Remarkably, by virtue of mammalian target of rapamycin/STAT3 Pi-Ser-727, Eps8 modulates FAK expression required for cell proliferation. Within 62% of colorectal tumor specimens examined, >2-fold enhancement of Eps8 as compared with their normal counterparts is observed, especially for those from the advanced stage. In agreement with the modulation of FAK by Eps8, the concomitant expression of these two proteins in tumor specimens is observed. Notably, Eps8 attenuation also impedes the motility of SW620 and WiDr cells, which can be rescued by ectopically expressed FAK. This finding discloses the indispensability of Eps8 and FAK in cell locomotion. These results provide a novel mechanism for Eps8-mediated FAK expression and activation in colon cancer cells.

Prohibitin in the pathogenesis of transitional cell bladder cancer

Our profiling experiment demonstrated that prohibitin 1 (PHB) was ubiquitously expressed in uroepithelial and urothelial carcinoma cell lines and exhibited a trend toward a positive relationship with tumor progression. The aim of this study was, therefore, to examine the potential role of PHB in multistage bladder carcinogenesis and predicting patient outcome. Immunohistochemical staining showed that PHB was overexpressed in 141 out of 167 cases (84.4%) of bladder cancer. This expression was positively related to met receptor overexpression (p = 0.04) and to multiple tumors (p = 0.05). Independent factors in predicting patient survival were multiple tumors (p = 0.002), muscle invasion (p = 0.003), and met overexpression (p = 0.05) in a multivariate analysis. Interestingly, patients with superficial bladder cancer overexpressing both PHB and met had a significantly lower recurrence-free survival rate than those not expressing PHB (p = 0.04). Taken together, our findings showed that PHB was activated at an early stage of carcinogenesis and that it may play a synergistic role with met in the progression of human bladder cancer. In addition, we demonstrated that genistein and justicidin A, natural chemoprevention agents, could suppress the expression of PHB in vitro. Thus, targeting PHB would be a useful approach for treating and preventing human bladder cancer.

Collaboration of RON and epidermal growth factor receptor in human bladder carcinogenesis

PURPOSE

Collaboration of heterologous receptor tyrosine kinases has emerged as an important paradigm in tumor progression. We recently proved that RON has an important role in human bladder carcinogenesis. Since epidermal growth factor receptor has been suggested to cross-talk with RON, we examined the significance of epidermal growth factor receptor in modulating RON associated tumorigenesis.

MATERIALS AND METHODS

The biological significance of collaboration between RON and epidermal growth factor receptor was examined in the TSGH8301, J82 and JR bladder cancer cell lines with different expression status. Immunoprecipitation and immunoblotting assays were done to investigate the interaction of RON with epidermal growth factor receptor in relation to epidermal growth factor receptor kinase inhibitor treatment. Time lapse wound healing monitoring and Transwelltrade mark assay were used for cell migration analysis and the effect on cell transformation was analyzed with foci formation assay. Finally, a bladder cancer cohort of 78 patients was studied for clinical significance by immunohistochemistry.

RESULTS

Epidermal growth factor receptor was directly associated with RON, irrespective of ligand stimulation. The siRNA experiment and epidermal growth factor receptor kinase inhibitors efficiently inhibited RON related biological effects, including mitogenesis, migration, anti-apoptosis and neoplastic transformation. Co-expression of RON/epidermal growth factor receptor was found in 26 of 78 patients (33.3%) with bladder cancer. It was significantly associated with tumor invasion (p < 0.05), the risk of local recurrence (p = 0.0003) and decreased patient survival (p = 0.04). Important indicators for patient survival were co-expression of RON and epidermal growth factor receptor (p = 0.001) and tumor staging (p = 0.05).

CONCLUSIONS

Cross-talk between epidermal growth factor receptor and RON exists in vivo. Thus, it should be considered in treatment planning for patients with bladder cancer.

Characterization of viral kinetics in patients with hepatitis B e antigen-positive chronic hepatitis B

A study was conducted during a 1 year follow-up to characterize the viral kinetics in hepatitis B e antigen (HBeAg)-positive chronic hepatitis B and to develop a model of predicting the probability of spontaneous HBeAg seroconversion. Fifty-seven patients with HBeAg-positive chronic hepatitis B were enrolled with monthly follow-ups from three Phase III clinical trial placebo groups. According to serial viral loads, 30 patients (52.6%) with the stationary pattern maintained stable HBV DNA levels with fluctuations of less than 1.5 log copies/ml. Twenty patients (35.1%) with the declining pattern exhibited a spontaneous decline of more than 1.5 log copies/ml without a following rebound of at least 1.5 log copies/ml. The remaining seven patients (12.3%) had the wavering pattern. Both declining and wavering patterns, when compared with the stationary pattern, had significantly higher hepatic necroinflammation in terms of ALT and Knodell scores at the baseline and peak ALT levels during the follow-up period. The declining pattern had a significantly better clinical outcome in terms of the lowest final HBV DNA and a reduction in the necroinflammatory score after 1 year. Furthermore, the declining pattern had a favorable HBeAg seroconversion rate (40%) compared with the wavering (14.3%) and stationary patterns (0%). A regression equation, incorporating simultaneous serum bilirubin, ALT, and HBV DNA levels, predicted the probability of HBeAg seroconversion with a sensitivity of 76.8% and a specificity of 74.7%. In conclusion, different viral kinetic patterns in patients with chronic hepatitis B implicate distinct clinical significance and immunologic perspective.