Significance of methylation status and the expression of RECK mRNA in lung tissue of patients with NSCLC

OBJECTIVES

RECK (reversion-inducing cysteine-rich protein with Kazal motifs) is a glycoprotein which negatively regulates the activity of matrix metalloproteinases (MMPs). We analyzed differences in RECK mRNA expression in histological types of non-small cell lung cancer (NSCLC) and the relationship between promoter methylation status of RECK gene, level of RECK mRNA expression and clinicopathological values of patients with NSCLC.

PATIENTS AND METHODS

Methylation status of the promoter and the expression of RECK mRNA were analyzed in paired tissue samples (tumor and control) of 50 patients with NSCLC. The methylation status of the RECK promoter was assessed using methylation-specific PCR. The level of RECK mRNA expression was measured using an RT real-time PCR method.

RESULTS

Lower expression of RECK mRNA in NSCLC tissue was recorded compared to normal tissue (p=0.0032). Significantly lower expression of RECK in squamous cell carcinoma (SCC) tissue was observed in comparison with adenocarcinoma tissue (p=0.0051). Significant differences in expression of RECK in stages IB-IIIA were found in comparison with stage IA (p=0.0455). There was a significantly lower expression of RECK mRNA in NSCLC tissue in samples with positive RECK promoter methylation status in comparison with samples with negative promoter methylation status (p=0.0400).

CONCLUSION

We showed that there were differences in expression between histological types of NSCLC (SCC, adenocarcinoma). There was a higher expression of RECK in stage IA in comparison with stages IB-IIIA. Our results indicate that RECK could be classified as a tumor suppressor gene and is an interesting target for further investigation of MMP inhibitors.

Clinical relevance of the expression of mRNA of MMP-7, MMP-9, TIMP-1, TIMP-2 and CEA tissue samples from colorectal liver metastases

BACKGROUND

Nowadays we know that survival rates do not differ between repeated and single liver resections for colorectal liver metastases (CLM). To be able to determine patients prone to early recurrence, the use of different markers with a better prognostic value than the routinely employed tumor markers is required.

AIM OF STUDY

The aim of our study was to assess mRNA expression of MMP-7, MMP-9, TIMP-1, TIMP-2 and CEA in tissue samples from CLM and their relationship to disease-free interval (DFI) and overall survival (OS).

PATIENTS AND METHODS

The liver tumor biopsies were obtained from 40 patients suffering from CLM treated with radical surgery. mRNA expression levels of CEA, MMPs and TIMPs and a housekeeping gene (GAPDH) were quantified using RT-PCR.

RESULTS

The increased expression of CEA, MMP-9 and TIMP-1 in CLM was associated with a short DFI and a high tendency to early CLM recurrence. Statistical analysis confirmed CEA, MMP-9 and TIMP-1 expression as prognostic factors of survival.

CONCLUSION

This study demonstrated the importance of CEA, MMP-9 and TIMP-1 in the prognostication of DFI and OS.

Clinicopathological assessment and quantitative estimation of the matrix metalloproteinases MMP-2 and MMP-7 and the inhibitors TIMP-1 and TIMP-2 in colorectal carcinoma tissue samples

BACKGROUND

The matrix metalloproteinases (MMP) are a family of proteolytic enzymes involved in tumor growth and in the process of invasion. The aim of our study was to test the levels of MMP-2, MMP-7, and the MMP inhibitors TIMP-1 and TIMP-2 mRNA in colorectal carcinoma tissue samples with the clinicopathological status of the disease.

PATIENTS AND METHODS

Colorectal carcinoma tissue samples were obtained from 38 patients who underwent resection of colorectal carcinoma. The expression levels of mRNA of MMP-2, MMP-7, TIMP-1, TIMP-2 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a housekeeping gene were quantified in these tissue samples using the method of reverse transcription real-time PCR.

RESULTS

It was found that the levels of mRNA expression of MMP-2, TIMP-2, MMP-7 and TIMP-1 were significantly higher in tumor tissue samples than in the normal colorectal tissue (p < 0.0020, p < 0.0467, p < 0.0007 and p < 0.0003 respectively). The level of mRNA expression of MMP-2, MMP-7, TIMP-2 and TIMP-1 did not correlate with the stage of the disease, localization of the tumor, metastatic spread or with disease-free survival (DFI). We recorded a statistically significant inverse negative correlation (r = -0.85; p < 0.0001) between the levels of MMP-7 mRNA and TIMP-2 mRNA. Correlations between the values of mRNA MMP-7 vs. TIMP-1, MMP-2 vs. TIMP-2, MMP-2 vs. TIMP-1 and MMP-2 vs. MMP-7 were not statistically significant.

CONCLUSION

We found that there were statistically significant differences in the levels of MMP-2, MMP-7, TIMP-1, TIMP-2 mRNA between normal colorectal tissue and tumor tissue, but we did not find any statistically significant correlation between mRNA levels of MMP-2, MMP-7, TIMP-1, TIMP-2 expression and localization of tumor, clinical stage or course of disease. We found an inverse negative statistically significant correlation between mRNA levels of MMP-7 and TIMP-2. On the basis of these results the clinical use of this approach to the determination of a prognosis is ambiguous.

The reliability of bonded lingual retainers

BACKGROUND

Bonded lingual retainers have become increasingly popular, but there is little information on their long-term reliability.

OBJECTIVES

The aims of this retrospective study were to investigate the reliability of bonded upper and lower lingual retainers and the factors contributing to their failure.

METHODS

The study group were 149 patients who returned between 2002 and 2005 with failed upper and/or lower fixed lingual retainers. Approximately 230 patients were debonded each year and approximately 1150 patients were covered annually by a 5-year guarantee of replacement or repair of failed retainers. The retainers were made from 0.018 inch round stainless steel heat-treated orthodontic wire. The upper retainers had loops opposite the embrasures and the lower retainers had loops between the lateral incisors and canines. The following details were recorded: teeth involved, patient gender, the likely cause of any damage and the time taken for each repair.

RESULTS

Between 35 and 40 patients required repair/replacement of their retainers each year. Multiple bond failures occurred in approximately 9 per cent of these patients. Male patients had twice the fracture rate of female patients. Extra-oral trauma was the most frequent cause of failure followed by intra-oral trauma, operator error and wire fracture. The central incisors in both arches were the most frequent sites of failure. Single tooth repairs required approximately 12 minutes of the orthodontist's chair-side time.

CONCLUSIONS

Bonded lingual retainers are a reliable form of retention after orthodontic treatment.

Migratory patterns and developmental potential of trunk neural crest cells in the axolotl embryo

Using cell markers and grafting, we examined the timing of migration and developmental potential of trunk neural crest cells in axolotl. No obvious differences in pathway choice were noted for DiI-labeling at different lateral or medial positions of the trunk neural folds in neurulae, which contributed not only to neural crest but also to Rohon-Beard neurons. Labeling wild-type dorsal trunks at pre- and early-migratory stages revealed that individual neural crest cells migrate away from the neural tube along two main routes: first, dorsolaterally between the epidermis and somites and, later, ventromedially between the somites and neural tube/notochord. Dorsolaterally migrating crest primarily forms pigment cells, with those from anterior (but not mid or posterior) trunk neural folds also contributing glia and neurons to the lateral line. White mutants have impaired dorsolateral but normal ventromedial migration. At late migratory stages, most labeled cells move along the ventromedial pathway or into the dorsal fin. Contrasting with other anamniotes, axolotl has a minor neural crest contribution to the dorsal fin, most of which arises from the dermomyotome. Taken together, the results reveal stereotypic migration and differentiation of neural crest cells in axolotl that differ from other vertebrates in timing of entry onto the dorsolateral pathway and extent of contribution to some derivatives.

The Trabecula cranii: development and homology of an enigmatic vertebrate head structure

Abstract

The vertebrate cranium consists of three parts: neuro-, viscero- and dermatocranium, which differ in both developmental and phylogenetic origin. Traditionally, developmental origin has been used as a criterion for homology, but this becomes problematic when skull elements such as the parietal bone are now shown, by modern fate-mapping studies, to have different developmental origins in different groups of tetrapods. This indicates a flexibility of developmental programmes and regulatory pathways which has probably been very important in cranial evolution. The trabecula cranii is an intriguing cranial element in the anterior cranial base in vertebrates. It forms a viscerocranial part of the neurocranium and is believed to be neural crest-derived in gnathostomes, but a similarly named structure in lampreys has been shown to have a mesodermal origin. Topographically, this trabecula seems to be homologous to the gnathostome trabecula cranii, and might also have the same function: to form a border between adjacent morphogenetic domains, to constrain and redirect growth of both brain and stomodeum and thus to refine developmental schedules of both. We suggest that such a border zone can recruit cells from either the mesoderm (as in the lamprey) or from the neural crest (as in the gnathostomes investigated), and still retain its homology. In our view, the trabecula is an interface element that integrates the respective divergent morphogenetics programs of the preotic head into a balanced unit; we suggest that such a definition can be used to define "the sameness" of this element throughout vertebrates.

Vertebrate head development: segmentation, novelties, and homology

Vertebrate head development is a classical topic lately invigorated by methodological as well as conceptual advances. In contrast to the classical segmentalist views going back to idealistic morphology, the head is now seen not as simply an extension of the trunk, but as a structure patterned by different mechanisms and tissues. Whereas the trunk paraxial mesoderm imposes its segmental pattern on adjacent tissues such as the neural crest derivatives, in the head the neural crest cells carry pattern information needed for proper morphogenesis of mesodermal derivatives, such as the cranial muscles. Neural crest cells make connective tissue components which attach the muscle fiber to the skeletal elements. These crest cells take their origin from the same visceral arch as the muscle cells, even when the skeletal elements to which the muscle attaches are from another arch. The neural crest itself receives important patterning influences from the pharyngeal endoderm. The origin of jaws can be seen as an exaptation in which a heterotopic shift of the expression domains of regulatory genes was a necessary step that enabled this key innovation. The jaws are patterned by Dlx genes expressed in a nested pattern along the proximo-distal axis, analogous to the anterior-posterior specification governed by Hox genes. Knocking out Dlx 5 and 6 transforms the lower jaw homeotically into an upper jaw. New data indicate that both upper and lower jaw cartilages are derived from one, common anlage traditionally labelled the "mandibular" condensation, and that the "maxillary" condensation gives rise to other structures such as the trabecula. We propose that the main contribution from evolutionary developmental biology to solving homology questions lies in deepening our biological understanding of characters and character states.

Quantitative estimation of matrix metalloproteinases 2 and 7 (MMP-2, MMP-7) and tissue inhibitors of matrix metalloproteinases 1 and 2 (TIMP-1, TIMP-2) in colorectal carcinoma tissue samples

BACKGROUND

An essential step in the process of tumor invasion and metastasis involves the degradation of tissue barriers in the extracellular matrix (ECM), particularly in the basal membrane (BM). Matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs), in particular MMP-2, MMP-7, TIMP-1 and TIMP-2, play an important role in the process of ECM and BM degradation in connection with tumor invasion. The aim of our study was to assess the levels of MMP-2, MMP-7, TIMP-1 and TIMP-2 mRNA expression in colorectal carcinoma tissue samples and to correlate them with the stage of the disease.

PATIENTS AND METHODS

The study included samples of tumor tissue of 38 patients with colorectal carcinoma and samples of tissue of 11 patients with benign disease. The expression levels of mRNA MMP-2, MMP-7, TIMP-1, TIMP-2 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), as housekeeping gene, were quantified in tissue samples using the method of reverse transcription real-time PCR.

RESULTS

The levels of mRNA expression of MMP-2, MMP-7 and TIMP-1 were significantly higher in tumor tissue samples that in the control tissue (p<0.0005, p<0.0007 and p<0.0004). In addition the presence of mRNA MMP-2, MMP-7, TIMP-1 and TIMP-2 in tumor tissue samples in these parameters was significantly higher than in the control tissue (p<0.003, p<0.0001, p<0.0001 and p<0.05).

CONCLUSION

This pilot study demonstrated that a significant difference in the level and in the presence of mRNA MMP-2, MMP-7 and TIMP-1 expressions between tumor colorectal and control colorectal tissues might be helpful for the prognosis of colorectal cancer.

Developmental origins and evolution of jaws: new interpretation of "maxillary" and "mandibular"

Cartilage of the vertebrate jaw is derived from cranial neural crest cells that migrate to the first pharyngeal arch and form a dorsal "maxillary" and a ventral "mandibular" condensation. It has been assumed that the former gives rise to palatoquadrate and the latter to Meckel's (mandibular) cartilage. In anamniotes, these condensations were thought to form the framework for the bones of the adult jaw and, in amniotes, appear to prefigure the maxillary and mandibular facial prominences. Here, we directly test the contributions of these neural crest condensations in axolotl and chick embryos, as representatives of anamniote and amniote vertebrate groups, using molecular and morphological markers in combination with vital dye labeling of late-migrating cranial neural crest cells. Surprisingly, we find that both palatoquadrate and Meckel's cartilage derive solely from the ventral "mandibular" condensation. In contrast, the dorsal "maxillary" condensation contributes to trabecular cartilage of the neurocranium and forms part of the frontonasal process but does not contribute to jaw joints as previously assumed. These studies reveal the morphogenetic processes by which cranial neural crest cells within the first arch build the primordia for jaw cartilages and anterior cranium.