The prognostic significance of circulating neuroendocrine markers chromogranin a, pro-gastrin-releasing peptide and neuron-specific enolase in patients with advanced non-small-cell lung cancer

Molecular and Clinical Implications of Somatostatin Receptor Profile and Somatostatin Analogues Treatment in Oral Cavity Squamous Cell Carcinoma

Simple Summary

The treatment of oral squamous cell carcinoma (OSCC) represents a significant problem worldwide. Among cancers with the highest incidence, OSCC renders one of the worst prognoses. Therefore, novel prognostic biomarkers and therapeutic tools to tackle OSCC are urgently needed. Somatostatin-analogues (SSA) are an invaluable therapeutic option in the treatment of several cancers. We aimed to determine the expression levels of all somatostatin-receptors (SSTs) in OSCC, compared to adjacent healthy control tissues, to analyze the relationship of SSTs expression with key clinical and histopathological data, and to explore the direct in vitro effect of different SSAs on OSCC cancer cells. Our findings highlight a potential role of SST₂ as a good prognostic biomarker for recurrence and metastasis in OSCC and unveil that SSA exerts antitumoral effects on OSCC cells, providing a relevant clinical conclusion, which should be soon tested for their use in humans.

Abstract

Oral squamous cell carcinoma (OSCC) incidence has increased by 50% over the last decade. Unfortunately, surgery and adjuvant radiotherapy and chemotherapy are still the mainstream modality of treatment, underscoring the need for alternative therapies. Somatostatin-analogues (SSA) are efficacious and safe treatments for a variety of tumors, but the presence of somatostatin-receptors (SSTs) and pharmacological effects of SSA on OSCC are poorly known. In this study, we demonstrated that SST₂ and SST₃ levels were significantly higher in OSCC, compared to adjacent healthy control tissues. SST₂ expression was associated with less regional metastasis and a lower recurrence rate. Moreover, SST₂ was elevated in OSCC and associated with histopathological good prognosis factors, such as high peritumoral inflammation, smaller depth of invasion, and expansive vs. infiltrative front of tumor invasion. Importantly, treatment with different SSA (octreotide, lanreotide, and pasireotide) significantly reduced cell-proliferation in OSCC primary cell cultures. Altogether, this study demonstrated that SST₂ is overexpressed in OSCC vs. healthy tissues and could represent a novel prognostic biomarker, since its expression is associated with tumors that show better prognostic factors and less recurrent rate. Moreover, our data unveil clear antitumoral effects of SSAs on OSCC, opening new avenues to explore their potential as targeting therapy to OSCC.

Incidental Finding of Squamous Cell Carcinoma on a 68Ga-DOTATATE PET Scan

Neuroendocrine tumors (NETs) are a relatively rare entity; however, the incidence and prevalence of these tumors are increasing, likely attributed to improved diagnostic accuracy. The diagnosis of suspected NETs is facilitated by clinical symptoms, laboratory test abnormalities such as elevated chromogranin-A, and other diagnostic modalities such as the use of computed tomography scans, magnetic resonance imaging scans, positron emission tomography (PET) scans, and biopsy. The expression of high levels of somatostatin receptors in NETs enables the use of a specialized PET scan using the radiolabeled somatostatin analogues 68Ga-DOTATATE. The sensitivity and specificity of 68Ga-DOTATATE PET is very high for the diagnosis of NETs, but the specificity decreases especially with no clear symptoms and with only borderline elevated tumor markers. We present a case of a suspected NET, which was initially diagnosed as a metastatic NET by virtue of a positive 68Ga-DOTATATE PET scan; however, on biopsy it was revealed to be a squamous cell carcinoma originating from the head and neck.

Progastrin-Releasing Peptide Precursor and Neuron-Specific Enolase Predict the Efficacy of First-Line Treatment with Epidermal Growth Factor Receptor (EGFR) Tyrosine Kinase Inhibitors Among Non-Small-Cell Lung Cancer Patients Harboring EGFR Mutations

Purpose

Lung cancer is the leading cause of cancer-related mortality and non-small-cell lung cancer (NSCLC) accounts for 80–90% of all lung cancers. However, biomarkers to predict the prognosis of NSCLC patients upon treatment with tyrosine kinase inhibitors remain unreliable. Different types of EGFR mutations can help predict the efficacy of tyrosine kinase inhibitor (TKI) treatment among advanced NSCLC patients harboring them. However, survival varies among individuals harboring the same mutation after targeted therapy. This study aimed to investigate the value of serum tumor markers (STMs) and EGFR mutations in the prognostic assessment of progression-free survival (PFS) in advanced-stage EGFR-mutated NSCLC.

Patients and Methods

A retrospective clinical review was performed on 81 NSCLC patients harboring EGFR mutations and for whom STM data, measured before commencement of first‐line treatment with tyrosine kinase inhibitors, were available. Associations among EGFR mutations, STMs, baseline clinical features, and PFS were analyzed. Kaplan−Meier method was used to plot survival curves, and Cox logistic regression models were used to identify independent prognostic factors.

Results

Exon 19 deletion (19-del) in EGFR, negative neuron-specific enolase (NSE), negative pro-gastrin-releasing peptide precursor (ProGRP) value, and “never smoking” status were significantly associated with improved PFS (P=0.007, P=0.001, P<0.001, and P<0.001, respectively). Multivariate Cox analysis revealed that 19-del in EGFR, never smoking, negative ProGRP value, and negative NSE were independent predictors of PFS.

Conclusion

This study demonstrated that 19-del in EGFR may predict longer PFS in advanced-stage EGFR-mutated NSCLC treated with TKIs. Additionally, longer PFS can be predicted by serum tumor markers with negative ProGRP value, negative NSE value before initial treatment, and “never smoking.” Therefore, in addition to the EGFR mutation type and smoking status, physicians can also prognosticate the PFS of tyrosine kinase inhibitors treatment according to the values of ProGRP and NSE before treatment.

Multifunctional neuron-specific enolase: its role in lung diseases

Neuron-specific enolase (NSE), also known as gamma (γ) enolase or enolase-2 (Eno2), is a form of glycolytic enolase isozyme and is considered a multifunctional protein. NSE is mainly expressed in the cytoplasm of neurons and neuroendocrine cells, especially in those of the amine precursor uptake and decarboxylation (APUD) lineage such as pituitary, thyroid, pancreas, intestine and lung. In addition to its well-established glycolysis function in the cytoplasm, changes in cell localization and differential expression of NSE are also associated with several pathologies such as infection, inflammation, autoimmune diseases and cancer. This article mainly discusses the role and diagnostic potential of NSE in some lung diseases.

Value of serum tumor markers for predicting EGFR mutations in non-small cell lung cancer patients

OBJECTIVES

We investigated whether serum tumor markers (STMs) represent a valuable noninvasive tool to predict epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients.

METHODS

A retrospective analysis was performed for 143 NSCLC patients at the Peking University International Hospital from December 2014 to December 2019. EGFR mutations in the tumor tissues were identified by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and next generation sequencing (NGS). The relationships between EGFR mutation and several clinicopathological features were analyzed.

RESULT

EGFR mutation were found more frequently in female (56.67%, P = 0.01), never-smokers (55.26%, P = 0.004), and those with lung adenocarcinoma (ADC) (52.17%, P < 0.001). The positive mutation rate for the EGFR gene were higher in the squamous cell carcinoma antigen (SCCA)group (≤1.5 ng/ml) and in the gastrin-releasing peptide precursor (preGRP) increased group (≥69.2 pg/ml), and this difference was statistically significant (P < 0.05). Univariate logistic regression analysis demonstrated that females (Odd ratio [OR]: 2.435, 95% confidence interval [CI]: 1.232, 4.813, P = 0.01) and never-smokers (OR = 0.370; CI = 0.186, 0.734; P = 0.004), lung adenocarcinoma patients (OR = 9.091; CI = 2.599, 21.800; P = 0.001), the SCC group (≤1.5 ng/ml) (OR = 0.331, CI = 0.120, 0.914; P = 0.033), and the preGRP group (≥69.2 pg/ml) (OR = 5.478, CI = 1.462, 20.528; P = 0.012) patients were risk factors for EGFR gene mutation. Multivariate logistic regression analysis demonstrated that lung ADC and proGRP elevation were independent risk factors for predicting EGFR gene positivity (P < 0.05).

CONCLUSION

STMs are associated with mutant EGFR status and could be integrated with other clinical factors to facilitate the classification of EGFR mutation status among NSCLC patients.

Predictive Value of 99MTC-hynic-toc Scintigraphy in Lung Neuroendocrine Tumor Diagnosis

Background:

Νeuroendocrine tumors of the lungs are rare arising in the thymus and gastro-entero-pancreatic tract and belonging to foregut of neuroendocrine tumors. The aim of the present prospective study was to estimate the potential impact of single-photon emission computed tomography somatostatin receptor scintigraphy using 99mTc-Tektrotyd on diagnosis, treatment response, and prognosis in patients with neuroendocrine tumors of the lungs.

Methods:

Thirty-six patients with neuroendocrine tumors of the lungs were evaluated by using 99mTc-HYNIC-TOC scintigraphy. The scintigraphic results were compared to liver tissue uptake (Krenning score). Likewise, the functional imaging results were compared with biochemical indices including chromogranin A, neuroendocrine-specific enolase, and insulin-like growth factor 1 at the time of diagnosis (baseline) and disease progression.

Results:

The number of somatostatin receptors, expressed with Krenning score, did not show any correlation with the survival of patients both at baseline (P = .08) and at disease progression (P = .24), and scintigraphy results did not relate significantly to progression-free survival. Comparing the results of 99mTc-HYNIC-TOC scintigraphy according to the response of patients in the initial treatment, a statistically significant negative correlation was observed both in the first and in the second scintigraphy with patients’ response (P = .001 and P < .001, respectively). The concentrations of biochemical markers were in accordance with scintigraphy results in the diagnosis.

Conclusion:

This study indicates that 99mTc-HYNIC-TOC scintigraphy appears to be a reliable, noninvasive technique for detection of primary neuroendocrine tumors and their locoregional or distant metastases, although it cannot be used as a neuroendocrine tumors of the lungs predictive technique.

LMO1 functions as an oncogene by regulating TTK expression and correlates with neuroendocrine differentiation of lung cancer

LMO1 encodes a protein containing a cysteine-rich LIM domain involved in protein-protein interactions. Recent studies have shown that LMO1 functions as an oncogene in several cancer types, including non-small cell lung cancer (NSCLC). However, the function of LMO1 in other histological subtypes of lung cancer, such as small cell lung cancer (SCLC), was not investigated. In analyzing the expression of LMO1 across a panel of lung cell lines, we found that LMO1 expression levels were significantly and dramatically higher in SCLC cells, an aggressive neuroendocrine subtype of lung cancer, relative to NSCLC and normal lung cells. In NSCLC cells, LMO1 mRNA levels were significantly correlated with expression of neuroendocrine differentiation markers. Our in vitro investigations indicated that LMO1 had the general property of promoting cell proliferation in lung cancer cells representing different histological subtypes, suggesting a general oncogenic function of LMO1 in lung cancer. In investigating the clinical relevance of LMO1 as an oncogene, we found that a high tumor level of the LMO1 mRNA was an independent predictor of poor patient survival. These results suggest that LMO1 acts as an oncogene, with expression correlated with neuroendocrine differentiation of lung cancer, and that it is a determinant of lung cancer aggressiveness and prognosis. By combining gene expression correlations with patient survival and functional in vitro investigations, we further identified TTK as mediating the oncogenic function of LMO1 in lung cancer cells.

A Case of Primary Combined Squamous Cell Carcinoma with Neuroendocrine (Atypical Carcinoid) Tumor in the Floor of the Mouth

The combined squamous cell carcinoma (SCC) with neuroendocrine (atypical carcinoid (AC)) tumor is extremely rare in the head and neck. We present here the first case of SCC with AC arising in the floor of the mouth of 65-year-old man. The tumor is comprised of two components of SCC and AC in the biopsy specimen. Neuroendocrine tumor component was classified as AC from the punctate necrosis and 2–10>/10 HPF. Immunohistochemical staining was HMW-CK/34B (+) and P63 (+) in SCC and synaptophysin (+) and CD56 (+) in AC. The pathological diagnosis of SCC with AC was made from both the morphological and immunological exam. Concurrent chemoradiotherapy was performed with radiotherapy 70.2 Gy and chemotherapy of CDDP and VP-16. Although the treatment effect was complete response both of primary tumor and of neck metastases, the recurrence of the primary tumor was after 6 months. Bilateral modified radical neck dissection and tumor resection of the floor of the mouth with reconstructive surgery of anterior lateral thigh free flap were performed. Although the primary and neck tumor did not recur, the multiple lung metastases and mediastinum lymph node metastases occurred at 6 months after surgery.

Immune therapy of non-small cell lung cancer. The future

Surgery is still the best treatment option of lung cancer but only one third of patients are operable and prognosis remains mediocre in operated patients, with the exception of initial stages. Medical treatment is fast moving toward new frontiers. New insights in the biology of cancer development led to discovery of new drugs, which are more effective as compared to conventional platinum based chemotherapy. A new approach to immunotherapy based on immune-check point represents a remarkable innovation in lung cancer treatment. Initial trials with anti PD-1 antibodies in metastatic patients provided results never observed with previously known drug categories. Several key question need to be answered to identify patients most likely to respond to anti PD-1/anti PD-L1 treatments, to assess the role of combined treatment modalities including immune check point receptor block (associations with surgery, chemotherapy, ITKs), and to boost host immune response, possibly by lowering his systemic inflammation and improving nutritional status.

NSE can predict the sensitivity to definitive chemoradiotherapy of small cell carcinoma of esophagus

Patients with esophageal small cell carcinoma undergoing definitive chemoradiotherapy (CRT) seem to have disparity in tumor response. The identification of CRT sensitivity-related tumor markers would be helpful for selecting patients most likely to benefit from CRT. The aim of this study was to examine the predictive value of biological markers in small cell carcinoma of the esophagus (SCEC) patients treated with definitive CRT. Pretreatment serum levels of neurone-specific enolase (NSE), cytokeratin 19 fragment antigen 21-1 (CYFRA21-1), and carcinoembryonic antigen (CEA) were measured by immunoradiometric assays, while the tumor responses were evaluated according to the World Health Organization response criteria. The relationships between pretreatment expression of NSE, CYFRA21-1, CEA, and the tumor response to CRT were analyzed. The effective rates (complete response + partial response) in NSE high and low groups were 10.80 % (9/82) and 37.98 % (31/82), respectively (P = 0.003).The results from statistical analysis indicated that the effectiveness of CRT was significantly associated with the serum levels of NSE before treatment (P = 0.002). The overall survival (OS) of the patients with high NSE levels was worse than that of those with low NSE levels (P = 0.004). In multivariate analysis, low level of NSE was the most significant independent predictor of good OS (P = 0.003). The result showed a promising predictive value of NSE regarding to the sensitivity of tumors to CRT. NSE may be a reliable surrogate marker of CRT efficacy in patients with SCEC.

Prognostic value of tumor markers, NSE, CA125 and SCC, in operable NSCLC Patients

The aim of this study was to investigate the prognostic value of tumor markers in operable non-small cell lung cancer (NSCLC) patients. A total of 481 NSCLC patients were enrolled in the present study. High levels of neuron-specific enolase (NSE), carbohydrate antigen 125 (CA125) and squamous cell carcinoma antigen (SCC) were detected in 306 (63.6%), 89 (18.5%) and 125 (26.0%) patients, respectively. Seventy-eight of 481 patients died of disease progression, and the median disease-free survival (DFS) and overall survival (OS) were 16.0 and 21.0 months, respectively. The three-year DFS rate was 56.7%, and the OS rate was 75.3%. For serum NSE, the three-year cumulative DFS rate for the normal and elevated group was 67.7% and 51.8% (p = 0.007). The OS in patients with high and normal levels of NSE was 34.0 months and 48.0 months, respectively. The median DFS was 46.0 months versus 32.0 months (p = 0.001), and the OS was 48.0 months versus 44.0 months (p = 0.001) in patients with normal and high levels of CA125. For patients with squamous cell carcinoma, the overall survival was significantly shorter in patients with elevated levels of SCC (p = 0.041). In the multivariate analysis high levels of NSE, CA125 and clinical stage were significantly correlated with worse prognosis (p < 0.05). Patients with all three tumor markers elevated presented the worst prognosis (p < 0.05). In our analysis, high levels of preoperative serum NSE and CA125 are correlated with worse survival in operable NSCLC patients.

Neuroendocrine differentiation in head and neck squamous cell carcinoma

OBJECTIVE

Tumours with neuroendocrine differentiation frequently express chromogranin A, synaptophysin and somatostatin receptors. The role of neuroendocrine differentiation in head and neck squamous cell carcinoma is not yet clear.

METHOD

The presence of chromogranin A, synaptophysin and somatostatin receptors was studied immunohistochemically in 78 head and neck squamous cell carcinoma specimens.

RESULTS

Sparse chromogranin A expression was found in 41 per cent, associated with high chromogranin A messenger RNA expression and the presence of dense core granules. Low synaptophysin expression was found in 18 per cent. The highest staining scores were found for somatostatin receptor 5 (82 per cent), followed by somatostatin receptor 1 (69 per cent) and somatostatin receptor 2 (54 per cent), whereas somatostatin receptors 3 and 4 expression was low. Expression was not correlated with tumour stage or survival.

CONCLUSION

Cells with neuroendocrine differentiation are sparsely scattered in some head and neck squamous cell carcinomas. Their pathophysiological role is elusive. In contrast, somatostatin receptor and particularly somatostatin receptor 5 expression is frequent in head and neck squamous cell carcinoma. Somatostatin receptor expression is not considered to indicate neuroendocrine differentiation in head and neck squamous cell carcinoma.

Characteristics and clinical validity of two immunoassays for ProGRP

Progastrin-releasing peptide (proGRP) is a promising serum tumor marker for small cell lung cancer (SCLC). We have tested assay specificity and performed a correlation study between a recently developed time-resolved immunofluorometric assay (TR-IFMA) for proGRP and the established Advanced Life Science Institute (ALSI) ELISA method. Between-method correlation and comparison of clinical performance were studied in 481 individuals, among them, 178 lung cancers, 84 benign diseases of the lung, and 219 healthy controls. Follow-up time >6 years was observed for 89 patients with SCLC. The two assays had quite different epitope specificities where the TR-IFMA recognized a considerable smaller proGRP fragment than the ALSI ELISA. However, the correlation between the two methods for elevated proGRP values (>85 ng/l) was good (ρ = 0.948). Both assays displayed good discrimination between benign lung diseases and SCLC. The cut-off values for positive classification of SCLC versus non-small cell lung cancers and benign lung diseases at >95% specificity were 85 ng/l for the TR-IFMA and 42 ng/l for the ALSI ELISA. Both proGRP assays showed good clinical validity. However, due to differences in the recommended cut-off values, switching methods is not recommended. There was a significant difference in survival of patients with TR-IFMA proGRP values over the cut-off (85 ng/l) compared with patients with values under the cut-off, p = 0.0002. In contrast, the ALSI ELISA assay failed to provide statistically significant prognostic information, p = 0.066.

Identification of five candidate lung cancer biomarkers by proteomics analysis of conditioned media of four lung cancer cell lines

Detection of lung cancer at an early stage is necessary for successful therapy and improved survival rates. We performed a bottom-up proteomics analysis using a two-dimensional LC-MS/MS strategy on the conditioned media of four lung cancer cell lines of different histological backgrounds (non-small cell lung cancer: H23 (adenocarcinoma), H520 (squamous cell carcinoma), and H460 (large cell carcinoma); small cell lung cancer: H1688) to identify secreted or membrane-bound proteins that could be useful as novel lung cancer biomarkers. Proteomics analysis of the four conditioned media allowed identification of 1,830 different proteins (965, 871, 726, and 847 from H1688, H23, H460, and H520, respectively). All proteins were assigned a subcellular localization, and 38% were classified as extracellular or membrane-bound. We successfully identified the internal control proteins (also detected by ELISA), kallikrein-related peptidases 14 and 11, and IGFBP2. We also identified known or putative lung cancer tumor markers such as squamous cell carcinoma antigen, carcinoembryonic antigen, chromogranin A, creatine kinase BB, progastrin-releasing peptide, neural cell adhesion molecule, and tumor M2-PK. To select the most promising candidates for validation, we performed tissue specificity assays, functional classifications, literature searches for association to cancer, and a comparison of our proteome with the proteome of lung-related diseases and serum. Five novel lung cancer candidates, ADAM-17, osteoprotegerin, pentraxin 3, follistatin, and tumor necrosis factor receptor superfamily member 1A were preliminarily validated in the serum of patients with lung cancer and healthy controls. Our results demonstrate the utility of this cell culture proteomics approach to identify secreted and shed proteins that are potentially useful as serological markers for lung cancer.

Gastrin-releasing peptide: different forms, different functions

All forms of the neuropeptide gastrin-releasing peptide (GRP) are derived from the precursor proGRP1-125. Amidated GRP18-27, which together with amidated GRP1-27 was long thought to be the only biologically relevant product of the GRP gene, is involved in a multitude of physiological functions and acts as a mitogen, morphogen, and proangiogenic factor in certain cancers. Recently, GRP has been implicated in several psychiatric conditions, in the maintenance of circadian rhythm, in spinal transmission of the itch sensation, and in inflammation and wound repair. The actions of GRP are mediated by the GRP receptor. Over the last decade, nonamidated peptides derived from proGRP, such as the glycine-extended form GRP18-28 and recombinant and synthetic fragments from proGRP31-125, have been shown to be biologically active in a range of tissues and in cancer cell lines. While GRP18-28 acts via the GRP receptor, the identity of the receptor for proGRP31-125 and its fragments has not yet been established. Nonamidated fragments are also present in normal tissues and in various cancers. In fact, proGRP31-98 is the most sensitive serum biomarker in patients with small cell lung cancer and is a significant predictor of poor survival in patients with advanced prostate cancer.

Terminal and progenitor lineage-survival oncogenes as cancer markers

Tumour classification has traditionally focused on differentiation and cellular morphology, and latterly on the application of genomic approaches. By combining chromatin immunoprecipitation with expression array, it has been possible to identify direct gene targets for transcription factors for nuclear hormone receptors. At the same time, there have been great strides in deriving stem and progenitor cells from tissues. It is therefore timely to propose that pairing the isolation of these cell subpopulations from tissues and tumours with these genomics approaches will reveal conserved gene targets for transcription factors. By focusing on transcription factors (lineage-survival oncogenes) with roles in both organogenesis and tumourigenesis at multiple organ sites, we suggest that this comparative genomics approach will enable developmental biology to be used more fully in relation to understanding tumour progression and will reveal new cancer markers. We focus here on neurogenesis and neuroendocrine differentiation in tumours.

Prognostic value of circulating chromogranin A and soluble tumor necrosis factor receptors in advanced nonsmall cell lung cancer

BACKGROUND

Increased levels of chromogranin A (CgA), a protein secreted by many neuroendocrine cells, have been detected in sera of patients with neuroendocrine tumors or renal, hepatic, or heart failure. In patients with heart failure, serum CgA correlates with tumor necrosis factor-alpha (TNF) and soluble TNF receptors (sTNF-Rs), with important prognostic implications. The prognostic value of CgA and sTNF-Rs was investigated in advanced nonsmall cell lung cancer (NSCLC), a histologically heterogeneous group of tumors that may undergo neuroendocrine differentiation.

METHODS

CgA and sTNF-Rs were analyzed in the sera of 88 patients with NSCLC before chemotherapy by enzyme-linked immunoadsorbent assay (ELISA) and in tumors by immunohistochemistry.

RESULTS

Thirteen percent of patients had CgA values greater than the highest value observed in normal subjects (distribution range, 9-724 ng/mL and 28-196 ng/mL, respectively). Immunohistochemical studies showed no correlation between CgA expression in tumors and serum levels. Conversely, circulating CgA was associated with worse Eastern Cooperative Oncology Group (ECOG) performance status (PS) (P = .0005), more advanced stage (P = .042), and survival, with CgA being an independent prognostic factor of poor outcome (hazards ratio [HR] 1.31 for 100 ng/mL increase; 95% confidence interval [95% CI], 1.08-1.60 [P = .0071]). sTNF-R1 and sTNF-R2 were also associated with ECOG PS (P = .0001 and P = .02, respectively). sTNF-Rs was weakly correlated with circulating CgA (r = 0.39 for TNF-R1 and r = 0.40 for TNF-R2), suggesting a regulatory link between sTNF-Rs and CgA secretion.

CONCLUSIONS

Increased serum levels of CgA in NSCLC are independent from protein expression in tumors and more likely related to neuroendocrine response associated with worsening of patient condition. In addition to ECOG PS and stage, CgA is an independent indicator of poor prognosis.

Gastrin-releasing peptide receptor as a molecular target in experimental anticancer therapy

Over the last two decades, several lines of experimental evidence have suggested that the gastrin-releasing peptide (GRP) may act as a growth factor in many types of cancer. For that reason, gastrin-releasing peptide receptor (GRPR) antagonists have been developed as anticancer candidate compounds, exhibiting impressive antitumoral activity both in vitro and in vivo in various murine and human tumors. In this article, the GRPR cell surface expression profile in human malignancies is reviewed aiming at the identification of potential tumor types for future clinical trials with GRP analogues and antagonists. In this review, we summarize the current literature regarding the GRPR status in human malignancies. Source data were obtained by searching all published material available through Medline, PubMed and relevant articles from 1971 to 2006. The data available demonstrated a high expression of GRPRs in a large spectrum of human cancers, demonstrating the potential relevance of this intracellular signaling pathway in various human tumor models. The GRPR may be an interesting target for therapeutic intervention in human malignancies, as carriers for cytotoxins, immunotoxins or radioactive compounds, being also a potential tool for tumor detection.

Investigation of the molecular profile of basal cell carcinoma using whole genome microarrays

Background

Skin cancer accounts for 1/3 of all newly diagnosed cancer. Although seldom fatal, basal cell carcinoma (BCC) is associated with severe disfigurement and morbidity. BCC has a unique interest for researchers, as although it is often locally invasive, it rarely metastasises. This paper, reporting the first whole genome expression microarray analysis of skin cancer, aimed to investigate the molecular profile of BCC in comparison to non-cancerous skin biopsies. RNA from BCC and normal skin specimens was analysed using Affymetrix whole genome microarrays. A Welch t-test was applied to data normalised using dCHIP to identify significant differentially-expressed genes between BCC and normal specimens. Principal component analysis and support vector machine analysis were performed on resulting genelists, Genmapp was used to identify pathways affected, and GOstat aided identification of areas of gene ontology more highly represented on these lists than would be expected by chance.

Results

Following normalisation, specimens clustered into groups of BCC specimens and of normal skin specimens. Of the 54,675 gene transcripts/variants analysed, 3,921 were differentially expressed between BCC and normal skin specimens. Of these, 2,108 were significantly up-regulated and 1,813 were statistically significantly down-regulated in BCCs.

Conclusion

Functional gene sets differentially expressed include those involved in transcription, proliferation, cell motility, apoptosis and metabolism. As expected, members of the Wnt and hedgehog pathways were found to be significantly different between BCC and normal specimens, as were many previously undescribed changes in gene expression between normal and BCC specimens, including basonuclin2 and mrp9. Quantitative-PCR analysis confirmed our microarray results, identifying novel potential biomarkers for BCC.