Expression of CD44 variant isoforms and association to the benign form of endocrine pancreatic tumours

CD44v10: An Antimetastatic Membrane Glycoprotein for Pancreatic Cancer

Aims

The aims of this study were 1) to investigate the mRNA pattern of CD44 variants in three primary (MIA PaCa 2, PANC-1, PSN-1) and two metastatic (CAPAN-1, SUIT-2) pancreatic cancer (PC) cell lines; 2) to ascertain whether the genetic transfer of CD44s and CD44v10 modifies the adhesion of PC cells to the extracellular matrix (ECM) in vitro and their metastatic behavior in vivo.

Methods

CD44 mRNA analysis was done by means of RT-PCR. Adhesion to ECM the was assessed using coated microtiter plates. For the study of CD44v10 insertion in the CAPAN-1 line, liposome-mediated DNA transfer was used. SCID mice were employed for in vivo experiments.

Results

CD44v10 mRNA was not expressed by the CAPAN-1 nor by four of the six SUIT-2-derived clones. The stable expression of CD44v10 by modified CAPAN-1 significantly enhanced fibronectin adhesion. Mice without either liver or pancreatic metastases were more frequently found among the animals injected with modified (CD44v10 expressing) than with non-modified CAPAN-1.

Conclusions

1) It is possible to differentiate between metastatic and non-metastatic PC cells on the basis of CD44v10 expression; 2) CD44v10 seems to be involved in mediating fibronectin adhesion in vitro and in counteracting metastases in vivo.

Hepatocyte nuclear factor (HNF)-1β and its physiological importance in endometriosis

Endometriosis is associated with pelvic pain and female infertility. Endometriosis induces inflammation and is vulnerable to oxidative stress damage. To update and summarize the literature concerning the mechanisms that serve to protect genomic DNA from the oxidative damage, the present study reviews the English-language literature for biochemical studies on the transcription factor hepatocyte nuclear factor (HNF)-1β target genes. Findings demonstrated that retrograde flow of the menstrual blood might give rise to endometriosis. Iron may have a significant impact on endometriosis gene expression. HNF-1β regulates tissue-specific gene expression in endometriosis, as well as the expression of several genes, including CD44v9, which binds several molecules, including hyaluronan, epidermal growth factor receptor (EGFR), leukemia-associated Rho-guanine nucleotide exchange factor (LARG), IQ motif containing GTPase activating protein 1 (IQGAP1), macrophage migration inhibitory factor (MIF), major histocompatibility complex, class II invariant chain (CD74), cystine transporter subunit (xCT), Fas and extracellular matrix (ECM) proteins. The CD44v9 system is involved in cell migration, growth, survival, anti-apoptosis, immune response and anti-oxidative stress through maintaining higher levels of antioxidants. HNF-1β may serve to alleviate damage and promote survival of cells experiencing stress by upregulating antioxidant protein expression. This review expands current knowledge on the molecular mechanisms underlying the oxidative stress protection provided by HNF-1β and provides evidence that elevated HNF-1β activity might be associated with the CD44v9-dependent signaling cascades.

Recent advances in understanding pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) are uncommon and have an incidence of approximately 4-5 per 1 000 000 people, accounting for 1%-2% of all pancreatic neoplasms. They usually grow slowly, eventually metastasize and lead to death. PETs can be classified as functioning or non-functioning tumors based on clinical manifestation. The pathogenesis of PETs may involve abnormal expression of CD10, CD44, CD99, p27, COX2, Ki-67, KIT, CK19, ARHI, RUNX1T1, and survivin genes, loss of heterozygosity on chromosomes, hypermethylation of tumor suppressor genes, and overexpression of ghrelin. Chromogranin A (CgA) has long been used as an important broad-spectrum marker for the identification of PETs. KIT and endoglin are new independent prognostic markers for PETs. The diagnosis is based on histopathology demonstrating neuroendocrine features such as positive staining for chromogranin A and specific hormones such as gastrin, proinsulin, vasoactive intestinal peptide (VIP) and glucagon. In addition to standard localization procedures, radiology diagnosis including computed tomography (CT), positron emission tomography and computed tomography (PET/CT), magnetic resonance imaging (MRI), ultrasound (US), endoscopic ultrasound (EUS), laparoscopic ultrasound (LUS), dynamic enhanced spiral CT, selective arterial stimulation and venous sampling (ASVS), and somatostatin receptor scintigraphy (SRS) are performed. Surgery is still one of the cornerstones in the management of PETs. Laparoscopy, and drugs of somatostatin analogs are routinely used. Understanding of the recent advances of PETs has important implications for the early diagnosis and treatment of PETs.

Pancreatic endocrine neoplasms: epidemiology and prognosis of pancreatic endocrine tumors

Pancreatic endocrine tumors (PETs) are uncommon tumors with an annual incidence <1 per 100 000 person-years in the general population. The PETs that produce hormones resulting in symptoms are designated as functional. The majority of PETs are non-functional. Of the functional tumors, insulinomas are the most common, followed by gastrinomas. The clinical course of patients with PETs is variable and depends on the extent of the disease and the treatment rendered. Patients with completely resected tumors generally have a good prognosis, and aggressive surgical therapy in patients with advanced disease may also prolong survival. The epidemiology, prognosis, and established and novel prognostic markers of PETs are reviewed.

Increased expression of SRp40 affecting CD44 splicing is associated with the clinical outcome of lymph node metastasis in human breast cancer

BACKGROUND

During the malignant transformation of breast tissues, the pre-mRNA precursor splicing of specific genes can be flexibly regulated, leading to the formation of different forms or amounts of mRNA in response to the cellular microenvironment, and is frequently associated with cell tumorigenesis and may even cause tumor metastasis. Regulation of pre-mRNA splicing by serine-arginine (SR)-rich phosphoprotein is hypothesized to be associated with tumor cell metastasis.

METHODS

We enrolled 55 breast cancer patients (32 with lymph node metastasis; LNM) with paired tissue samples consisting of cancerous and tumor-adjacent normal portions and assayed these tissues for gene expression of the SR family using quantitative real-time RT-PCR (qRT-PCR), then evaluated an association with LNM of breast cancer. Furthermore, we examined whether increased expression of a specific SR gene was associated with the presence of specific CD44 spliced variants using qualitative reverse-transcription PCR (RT-PCR).

RESULTS

Support for our hypothesis came from the observations that breast tumor tissues displayed higher level of SRp40 expression as compared with the paired non-cancerous tissues, which manifested the significant association between increased SRp40 expression and LNM (OR=4.48, 95% CI, 1.08-19.50, P=0.018). In addition, the primary tumors of breast with increased expression of SRp40 gene were associated with the presence of the large CD44 inclusion variants, CD44v2, CD44v3, CD44v5, and CD44v6 (P<0.05).

CONCLUSION

Increased expression of SRp40 can be detected in breast tumor tissues with a high degree of sensitivity, and that higher expression of SRp40 closely correlates with alternative pre-mRNA splicing of CD44, which may serve as an earlier marker in predicting the risk to breast cancer patients of developing LNM.

Nonductal neoplasms of the pancreas

Although the majority of pancreatic neoplasms are infiltrating ductal adenocarcinomas or other neoplasms with ductal differentiation, neoplasms with acinar, endocrine, mixed, or uncertain differentiation constitute a diverse and distinctive group. The most common and best-characterized nonductal neoplasms are pancreatic endocrine neoplasm, acinar cell carcinoma, pancreatoblastoma, and solid pseudopapillary neoplasm. This review details the clinical and pathologic features of these nonductal neoplasms, highlighting diagnostic criteria including the use of specific immunohistochemical stains to define the cellular differentiation of the neoplasms.

The molecular genetics of gastroenteropancreatic neuroendocrine tumors

The pathobiology of neuroendocrine tumors (NETs) is hampered by the lack of scientific tools that define their mechanisms of secretion, proliferation, and metastasis; and, currently, there are no accurate means to assess tumor behavior and disease prognosis. Molecular biologic techniques and genetic analysis may facilitate the delineation of the molecular pathology of NETs and provide novel insights into their cellular mechanisms. The current status and recent advances in assessment of the molecular basis of tumorigenesis of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) were reviewed (1981-2004). The objectives of this retrospective study were to provide a cohesive overview of the current state of knowledge and to develop a molecular understanding of these rare tumor entities to facilitate the establishment of therapeutic targets and rational management strategies. Multiple differences in chromosomal aberration patterns were noted between gastrointestinal (GI) neuroendocrine and pancreatic endocrine tumors (PETs). Divergence in gene expression patterns in the development of GI carcinoids and PETs was identified, whereas examination of the PET and GI carcinoid data demonstrated only few areas of overlap in the accumulation of genetic aberrations. These data suggest that the recent World Health Organization classification of GEP-NETs may require updating. In addition, previous assumptions of tumor similarity (pancreatic vs. GI) may be unfounded when they are examined at a molecular level. On the basis of the evolution of genetic information, enteric neuroendocrine lesions (carcinoids) and PETs may need to be classified as two distinct entities rather than grouped together as the single entity "GEP-NETs."

In vivo cervical cancer growth inhibition by genetically engineered cytotoxic T cells

PURPOSE

The CD44 v7/8 splice variant that is frequently expressed in cervical carcinoma and rarely expressed in normal tissues displays promising properties as a target antigen for cancer immune therapy. In this study, cytotoxic T lymphocytes (CTLs) were genetically engineered to gain CD44v7/8 target specificity.

METHODS

Clone 96 (Cl96), an established murine cytotoxic T-cell line, and naïve murine T cells were retrovirally transduced with a fusion gene construct encoding for the single chain fragment scFv of the monoclonal antibody VFF17 and for the zeta chain of the T-cell receptor (TCR). The therapeutic potential of genetically engineered T cells was tested in vitro and in vivo.

RESULTS

Surface expression of the chimeric TCR on infected Cl96 and naïve T cells was shown by FACS analysis. CD44v7/8-positive target cells were efficiently lysed by transduced Cl96 and naïve T cells, demonstrating the functionality and specificity of the chimeric TCR. In a xenograft BALB/c mouse model, efficient growth retardation of CD44v7/8-positive tumours was mediated by genetically engineered Cl96(VFF17)cyYZ cells.

CONCLUSIONS

We were able to reprogramme the target specificity of recombinant Cl96 and naïve CTLs resulting in efficient cytolysis of CD44v7/8-positive cervical cancer cells. High transduction rates and the specific cytolysis of CD44v7/8-redirected CTLs are promising tools for an immune gene therapy approach for advanced cervical cancer.

Cytokeratin 19 Is a Powerful Predictor of Survival in Pancreatic Endocrine Tumors

The prediction of the behavior of pancreatic endocrine tumors (PETs) is a difficult exercise. CK19, a marker of pancreatic ductal cells, does not stain normal islet cells. Our aim was to evaluate the prognostic value of traditional parameters, including the Capella classification, as well as CK19. We evaluated the clinicopathologic features of 101 curatively resected PETs. The influence on survival of size, functional status of tumor, growth pattern, nuclear grade, mitoses (>2/10 HPF), vascular and perineural invasion, and necrosis was determined. Immunohistochemistry for Ki-67 and CK19 was performed in 45 and 54 cases, respectively. Cases were categorized as per the Capella classification as: benign, borderline, low-grade, and high-grade malignant. The different variables were tested by standard univariate and multivariate analyses. Mitoses (P = 0.03), solid pattern (P = 0.04), necrosis (P = 0.01), vascular invasion (P = 0.003), perineural invasion (P = 0.02), CK19 staining (P = 0.0008), and Ki-67 (P = 0.02) were significant prognostic indicators by univariate analysis while the Capella classification was not significant. By multivariate analysis, only CK19 was significant (P = 0.0008). None of the CK19-negative cases died of disease, while 10 of 28 CK19-positive cases died of disease and 3 are alive with disease. The Capella classification includes malignant tumors in its benign and borderline categories. CK19 is a powerful predictor of survival and can potentially segregate benign and malignant PETs. We suggest that all PETs with any one of the following features be diagnosed as malignant: presence of necrosis, vascular invasion, perineural invasion, or CK19 positivity. We hypothesize that a subgroup of PETs may share a common histogenesis with pancreatic adenocarcinomas.

Molecular insights into gastrointestinal neuroendocrine tumours: importance and recent advances

A subset of gastrointestinal neuroendocrine tumours (carcinoids and pancreatic endocrine tumours) show aggressive growth. Early identification of this subset is essential for management; however, clinical, laboratory and histologic features frequently fail to achieve this. Currently, there is an increased understanding of the molecular pathogenesis/changes in neuroendocrine tumours and this may identify important prognostic factors and possibly, new treatments. Recent findings and progress in this area are briefly reviewed in this article.

Review of the clinical, histological, and molecular aspects of pancreatic endocrine neoplasms

Pancreatic endocrine neoplasms (PENs) are rare tumors, and little is known about their genetic and chromosomal alterations. Elucidation of the molecular events involved in PEN carcinogenesis has been hindered by the fact that PENs have been considered a single disease entity. The emergence of novel molecular characterization strategies has, however, made it apparent that these lesions exhibit diverse molecular fingerprints, which will facilitate the precise delineation of PEN prognosis, histopathology, and carcinogenesis.