Study of matrix metalloproteinases and their inhibitors in prostate cancer

BACKGROUND

Extracellular matrix metalloproteases (MMPs) have raised an extraordinary interest in cancer research because of their potential role in basal membrane and extracellular matrix degradation, consequently facilitating tumour invasion and metastases development.

METHODS

An immunohistochemical study was performed using tissue arrays and specific antibodies against MMPs 1, 2, 7, 9, 11, 13, 14, and their tissue inhibitors, TIMPs 1, 2 and 3. More than 2600 determinations on cancer specimens from 133 patients with clinically localised prostate carcinoma, 20 patients with prostatic intraepithelial neoplasia and 50 patients with benign prostate hyperplasia and controls, were performed.

RESULTS

When compared with benign pathologies, prostate carcinomas had higher expression of all MMPs and TIMPs. Dendogram shows a first-order division of tumours into two distinct MMPs/TIMPs molecular profiles, one of them with high MMPs/TIMs expression profile (n=70; 52.6%). Tumours with high expression of MMP-11 or -13, or cluster thereof, were significantly associated with higher probability of biochemical recurrence.

CONCLUSION

The expression of MMPs and TIMPs seems to have an important role in the molecular biology of prostate carcinomas, and their expression by tumours may be of clinical interest to used as indicators of tumour aggressiveness.

Expression of metalloproteases and their inhibitors in different histological types of breast cancer

PURPOSE

Metalloproteases (MMPs) and their tissue inhibitors of metalloproteases (TIMPs) are involved in several key aspects of tumoral growth, invasion and metastasis. The purpose of this study was to characterize on how the different histological types of breast cancer differ in the expression of several components of this enzymatic system.

METHODS

An immunohistochemical study was performed in 50 ductal, 23 lobular, 14 mucinous, 7 tubular, 4 papillary and 5 medullary invasive carcinomas, using tissue arrays and specific antibodies against 7 MMPs and 3 tisullar TIMPs. Staining results were categorized by means of a specific software program (score values).

RESULTS

Carcinomas of the ductal type showed higher score values for MMPs and TIMPs than the other histological types; whereas mucinous carcinomas had lower scores values for expressions of the majority of these proteins. Stromal fibroblasts were more frequently positive for MMP-1, -7 and -13 and TIMP-1 and -3, when present in carcinomas of the ductal type than in other histological types of breast carcinomas. Stromal mononuclear inflammatory cells were more frequently positive for MMP-1 and TIMP-3, but more often negative for MMP-7, -9 and -11, when located in carcinomas of the ductal type than in other histological types of breast carcinomas.

CONCLUSIONS

We found variations in MMP/TIMP expressions among the different histological subtypes of breast carcinomas suggesting differences in their tumor pathophysiology.

The vagus and recurrent laryngeal nerves in experimental congenital diaphragmatic hernia

BACKGROUND

The etiology of the anatomic and functional abnormalities of the esophagus in infants surviving congenital diaphragmatic hernia (CDH) remains unclear. We showed previously that fetal rats with CDH have malformations of neural crest-derived structures. The aim of this study was to examine the anatomy of the vagus and the recurrent laryngeal nerves, both of neural crest origin, in rats with CDH.

METHODS

We used the nitrofen-induced CDH fetal rat model. Nine control fetuses from four dams and nine fetuses with CDH from seven dams were included in this study. Embryos were fixed in formalin and a thoracic block from the larynx to tracheal bifurcation was serially sectioned in the horizontal plane. One in every ten sections was stained with hematoxylin and eosin. The image was digitalized using biological software (TDR-3dbase). Vagus and recurrent laryngeal nerves, trachea, esophagus and the great vessels were examined. In order to obtain the three-dimensional reconstructions, 90-120 consecutive images were used.

RESULTS

In comparison with controls there were striking abnormalities of the vagus and the recurrent laryngeal nerves in fetuses with CDH: (1) absence of the left (2/9) or right (2/9) vagus nerves; (2) absence of the left (3/9) or right (3/9) recurrent laryngeal nerves; (3) marked hypoplasia of the trunk of the vagus (2/9); (4) deviations of their normal course and change of normal anatomical relationships into the mediastinum (2/9); and (5) abnormal branching of the lower portion of the vagus (1/9).

CONCLUSIONS

Rat fetuses with CDH have anomalies of the vagus and recurrent laryngeal nerves that support the concept of a neural crest involvement in the origin of this malformation. 3-D reconstructions allow a detailed analysis and provide a precise insight into the real anatomy. These observations may explain esophageal motility disorders in CDH.

Expression of metalloproteases and their inhibitors by tumor and stromal cells in ductal carcinoma in situ of the breast and their relationship with microinvasive events

AIMS

This study aimed to investigate the expression of matrix metalloproteases (MMPs) and their inhibitors (TIMPs) in ductal carcinoma in situ (DCIS).

METHODS

We used inmunohistochemistry to compare the expression of MMPs and TIMPs in tumor or stromal cells for 50 pure DCIS and 12 DCIS with microinvasive foci.

RESULTS

Score values for collagenase-1 (MMP-1), membrane type 1 MMP (MMP-14), and TIMP-1, were significantly higher in pure DCIS than in DCIS with microinvasive foci, whereas stromalysin-3 (MMP-11) expression was significantly higher in DCIS with microinvasive foci. Both fibroblasts and mononuclear inflammatory cells (MICs) surrounding pure DCIS showed more frequently expression of MMP-1, MMP-14, and TIMP-3, whereas MMP-11 expression was more frequent in MICs of microinvasive tumors. MICs of microinvasive foci more frequently showed the expression of gelatinase A (MMP-2), MMP-11, collagenase-3 (MMP-13), and TIMP-1, than MICs surrounding pure DCIS; whereas peri-ductal MICs and fibroblasts from pure DCIS expressed TIMP-3 more commonly than these cells at microinvasive foci.

CONCLUSIONS

There are significant differences in the expression of MMPs and TIMPs, so in tumor cells and stromal cells, between pure DCIS and DCIS with microinvasive foci. Therefore, these staining patterns might display potential applications as biological markers, such as in evaluating microinvasion in resection specimens of breast tumors.

Critical assessment of the methods used for detection of bacterial translocation

AIM

Bacterial translocation (BT) can be demonstrated by blood and lymph node cultures and also by polymerase chain reaction (PCR) detection of DNA of enteric bacteria. Aiming at investigating BT after gastrointestinal operations we assessed it on two endpoints after ischemia-reperfusion (IR) or sham operation (SO).

METHODS

2 groups of 200-g Brown Norway male rats were treated as follows: SO animals ( n=12) had laparotomy alone and IR animals ( n=12) had successively 15 min clamping of the portal vein and the mesenteric artery. Half the animals in each group were killed on postoperative (p.o.) day 2 the other half on p.o. day 7. Under sterile conditions regional lymph nodes and vena cava and portal vein blood samples were recovered and cultured for aerobes and anaerobes. Escherichia coli beta-galactosidase DNA was assessed in blood samples by PCR. The findings in the two groups were compared by means of chi(2) tests.

RESULTS

Post-hepatic (peripheral blood) BT was detected by cultures of gram-negative bacteria in 16% and 0% of SO and IR animals, respectively, on p.o. day 2 and in 16% and 50% on p.o. day 7. These differences were not significant (ns). E. coli DNA was found in one SO rat. Pre-hepatic BT (portal blood and/or lymph nodes) of gram-negative bacteria was found in 16% and 33%, respectively, on day 2 and in 16% and 16% on day 7 (ns). However, if gram-positive cultures were taken into account, the figures were 66% and 66% on day 2 and 66% and 83% on day 7 (ns). No anaerobes could be cultured.

CONCLUSIONS

(1) BT is frequent in surgically manipulated animals. (2) To limit the assessment of BT to Enterobacteriaceae is probably misleading, since consistent amounts of gram-positive bacteria are found in the pre-hepatic territory. (3) PCR tests limited to E. coli DNA alone are likely incomplete. (4) Short periods of vascular clamping do not increase BT on the two endpoints selected in comparison with SO animals.

[Thyroid C cells are decreased in experimental CDH]

BACKGROUND/AIM

Experimental CDH is often associated with malformations of neural crest origin. Several of these features are present in human CDH and therefore likely similar pathogenic mechanisms should be explored. The aim of the present study is to examine whether thyroid C-cells, another neural crest derivative, are abnormal in this rat model.

METHODS

Pregnant rats were exposed either to 100 mg of 2-4-dichlorophenyl-p-nitrophenyl ether (nitrofén) or vehicle (controls) on 9.5 day of gestation. Fetuses were recovered on day 21st and the thyroids of those with CDH (68%) were immuno-histochemically stained with anti-calcitonin antibody. The number of positively stained cells per high power field were counted using a computer-assisted image analysis method in at least 5 sections per thyroid. The distribution of the cells within the gland was assessed as well. Comparisons between CDH and control rats were made by non-parametric tests with a significance threshold of p<0.05.

RESULTS

The number of c-cells was dramatically reduced in CDH animals in comparison with controls (101.2 +/- 61.3 vs 23.1 +/- 37, p<0.0001). Histology of the thyroid was similar in both groups, but the distribution of positive C-cells within the gland followed an abnormal pattern in CDH rats with the cells tending to be located at the periphery rather than at the core of the lobes.

CONCLUSIONS

Nitrofén induces a severe decrease in thyroid C cells accompanied by abnormal distribution patterns. These results add further evidence of the involvement of a neural crest dysregulation as a component of the pathogenesis of experimental CDH. Whether there is or not a clinical counterpart to these findings is still unknown, but the nature of the cardiovascular and craneo-facial malformations in some babies with CDH strongly support further research in this field.

[Aplication of a 3D reconstruction model for the analysis of nitrofen induced intrathoracic malformations]

BACKGROUND

Three dimensional computer-assisted reconstruction offers some adventages for analysis and comparison of biological phenomena and anatomical structures. The CDH nitrofen-induced animal model associates multiple anomalies in neural-crest derived tissues. The goal of this study is to analyse by a 3-D reconstruction software the malformations in the extrinsic innervation of the esophagus in this model.

METHODS

Nine control fetuses from 4 dams and 9 fetuses with CDH from 7 dams were studied. A thoracic block from the larynx to tracheal bifurcation was serially sectioned in the horizontal plane in every embryo. One in every 10 sections was stained with HE. The image was digitalized using biological software (TDR-3dbase). Vagus and recurrent laryngeal nerves, trachea, esophagus and the great vessels were examined. In order to obtain the 3-D reconstructions, 90 to 120 consecutive images were used.

RESULTS

In comparison with controls there were striking abnormalities of these nerves in fetuses with CDH: 1) Absence of the left (2/9) or right (2/9) vagus nerves. 2) Absence of the left (3/9) or right (3/9) recurrent laryngeal nerves. 3) Marked hypoplasia of the trunk of the vagus (2/9). 4) Deviations of their normal course and change of normal anatomical relationships into the mediastinum (2/9).

CONCLUSIONS

To fullfill our goals 3-D reconstructions allow a detailed analysis and provide a precise insight into the real anatomy. Rat fetuses with CDH have anomalies of the vagus and recurrent laryngeal nerves that support the concept of a neural crest involvement in the origin of this malformation. These observations may explain esophageal motility disorders in CDH.