Cancer invasion and tissue remodeling--cooperation of protease systems and cell types

Proteolytic degradation of the extracellular matrix plays a crucial role in both cancer invasion and non-neoplastic tissue remodeling processes. In human cancers the components of matrix degrading protease systems (uPA, uPAR, PAI-1 and MMPs) can be expressed by either the non-neoplastic stromal cells, the cancer cells or both. Studies of the prognostic impact of these components in human cancer and the effect of targeted gene inactivation on cancer metastasis in mice support the assumption that proteases promote cancer progression, independent of whether they are expressed by cancer cells or stromal cells. The pattern of expression of components of protease systems is usually very similar in different cases of the same type of cancer, while it varies between different types of cancer. There are intriguing similarities between the cellular expression pattern of components of protease systems seen in cancer invasion and in certain types of non-neoplastic tissue remodeling. We propose that cancer invasion can be viewed as tissue remodeling gone out of control. The stromal cell involvement in cancer invasion represents a new paradigm with important implications for cancer pathophysiology and cancer therapy.

Lactational competence and involution of the mouse mammary gland require plasminogen

Urokinase-type plasminogen activator expression is induced in the mouse mammary gland during development and post-lactational involution. We now show that primiparous plasminogen-deficient (Plg(−/−)) mice have seriously compromised mammary gland development and involution. All mammary glands were underdeveloped and one-quarter of the mice failed to lactate. Although the glands from lactating Plg(−/−) mice were initially smaller, they failed to involute after weaning, and in most cases they failed to support a second litter. Alveolar regression was markedly reduced and a fibrotic stroma accumulated in Plg(−/−) mice. Nevertheless, urokinase and matrix metalloproteinases (MMPs) were upregulated normally in involuting glands of Plg(−/−) mice, and fibrin did not accumulate in the glands. Heterozygous Plg(+/−) mice exhibited haploinsufficiency, with a definite, but less severe mammary phenotype. These data demonstrate a critical, dose-dependent requirement for Plg in lactational differentiation and mammary gland remodeling during involution.

Receptor binding and tyrosine kinase activation by insulin analogues with extreme affinities studied in human hepatoma HepG2 cells

The insulin-receptor affinity of five human insulin analogues with one to four amino acid substitutions was measured with human hepatoma cells (HepG2). The binding affinities ranged from 0.05% for AspB25 insulin, 18% for AspB9, GluB27 insulin, 80% for AspB28 insulin, and 327% for AspB10 insulin to 687% for HisA8, HisB4, GluB10, HisB27 insulin relative to human insulin. Binding constants obtained by competition experiments at steady state with [125I]TyrA14-labeled insulin and unlabeled analogues and by kinetic studies with [125I]TyrA14-labeled analogues and insulin gave essentially the same values. The kinetic studies showed that differences in affinity between analogues were due to differences in both dissociation and association rate constants. The affinity for insulinlike growth factor I receptor was low, ranging from less than 0.005% for AspB25 insulin to 0.6% for HisA8, HisB4, GluB10, HisB27 insulin. The potencies of insulin analogues in activation of the tyrosine kinase of solubilized and partially purified insulin receptors from HepG2 cells, measured with the exogenous substrate poly(Glu80-Tyr20), ranked in the same order as the binding affinities, the actual values being somewhat elevated for the high-affinity analogues, however. We conclude that these human insulin analogues are active in insulin-receptor binding and tyrosine kinase stimulation but show wide variation in affinity.

Glomerular epithelial foot processes and filtration slits in IDDM patients

Diabetic nephropathy is associated with functional changes in the glomerular filtration barrier but the structural counterpart remains unknown. Width of glomerular epithelial cell foot processes and of filtration slits were determined by morphometric methods in 11 non-diabetic kidney donors and in 28 diabetic patients with albumin excretion rates ranging from normal to proteinuria. Foot process width was estimated from the ratio of tuft surface density to length density of slits. At high magnification independently sampled, perpendicularly cut slits were classified. Foot process width on peripheral basement membrane was increased in microalbuminuric compared to normoalbuminuric diabetic patients (p<0.05) but showed no significant correlation with the level of albumin excretion when patients with increased barrier permeability were considered. Width of filtration slits in normo- and microalbuminuric diabetic patients exceeded that in non-diabetic control subjects (p<0.05). Filtration slits were narrower in patients with overt proteinuria than in patients with microalbuminuria (p<0.05) and correlated with glomerular filtration rate in all of the diabetic patients (r=0.65, p<0.005). The results show that insulin-dependent diabetic patients with nephropathy present changes of epithelial cells and filtration slits, demonstrable already in the stage of microalbuminuria. The mechanism of albumin leakage is not achieved by these measures. The dimension of filtration slits may play a contributing role in the level of glomerular filtration rate in diabetic patients.

Characterization of recombinant human HBP/CAP37/azurocidin, a pleiotropic mediator of inflammation-enhancing LPS-induced cytokine release from monocytes

Neutrophil-derived heparin-binding protein (HBP) is a strong chemoattractant for monocytes. We report here for the first time the expression of recombinant HBP. A baculovirus containing the human HBP cDNA mediated in insect cells the secretion of a 7-residue N-terminally extended HBP form (pro-HBP). Deletion of the pro-peptide-encoding cDNA sequence resulted in correctly processed HBP at the N-terminus. Electrospray mass spectrum analysis of recombinant HBP yielded a molecular weight of 27.237 +/- 3 amu. Consistent with this mass is a HBP form of 225 amino acids (mature part +3 amino acid C-terminal extension). The biological activity of recombinant HBP was confirmed by its chemotactic action towards monocytes. Furthermore, we have shown that recombinant HBP stimulates in a dose-dependent manner the lipopolysaccharide (LPS)-induced cytokine release from human monocytes.

Messenger RNA for membrane-type 2 matrix metalloproteinase, MT2-MMP, is expressed in human placenta of first trimester

An intimately regulated cell surface activation of matrix metalloproteinases (MMPs) is believed to be of critical importance for the control of trophoblast invasion. A histological investigation of the expression and localization of three different MMPs, the membrane-type matrix metalloproteinases 1 and 2 (MT1-MMP, MT2-MMP) and matrix metalloproteinase 2 (MMP-2/gelatinase A) was performed by in situ hybridization on consecutive sections from human placentae of first trimester pregnancies. Cytokeratin immunostaining identified trophoblast cells. Both normal and tubal implantation sites were studied. We observed a high degree of coexpression of MT2-MMP, MT1-MMP and MMP-2 mRNAs in single extravillous cytotrophoblasts that had invaded the endometrium and tubal wall. Furthermore, mRNAs for all three genes were also seen in cytotrophoblasts of cell islands. In contrast to this coexpression pattern, MT2-MMP expression was absent from cell columns and decidual cells, in which signals for MT1-MMP and MMP-2 mRNAs were seen. The present data on the cellular expression of MT2-MMP mRNA in placenta extend our knowledge of the proteolytic events that take place during early pregnancy. The data suggest that MT2-MMP, capable of activating MMP-2 in vitro, is involved in the invasion of extravillous cytotrophoblast, possibly related to the physiological activation of MMP-2.

Co-ordinated expression of MMP-2 and its putative activator, MT1-MMP, in human placentation

The spatial expression of mRNA for matrix metalloproteinase 2 (MMP-2), its putative activator, the membrane-type 1 matrix metalloproteinase (MT1-MMP), and the MMP-2 substrate type IV collagen was investigated in human placentas of both normal and tubal ectopic pregnancies and in cyclic endometrium using in-situ hybridization. Cytokeratin staining applied to adjacent sections was used to identify epithelial and trophoblast cells. In both normal and tubal pregnancies MT1-MMP, MMP-2 and type IV collagen mRNA were highly expressed and co-localized in the extravillous cytotrophoblasts of anchoring villi, in cytotrophoblasts that had penatrated into the placental bed and in cytotrophoblastic cell islands. In addition, the decidual cells of normal pregnancies in some areas co-expressed MT1-MMP and MMP-2 mRNA, with moderate signals for both components. Fibroblast-like stromal cells in tubal pregnancies were positive for MMP-2 mRNA but generally negative for MT1-MMP mRNA. The consistent co-localization of MT1-MMP with MMP-2 and type IV collagen in the same subset of cytotrophoblasts strongly suggests that all three components co-operate in the tightly regulated fetal invasion process. The co-expression of MT1-MMP and MMP-2 mRNA in some of the decidual cells indicates that these cells are also actively involved in the placentation process.

The 1.6 A structure of Kunitz-type domain from the alpha 3 chain of human type VI collagen

The C-terminal Kunitz-type domain from the alpha 3 chain of human type VI collagen (C5), a single 58 amino acid residue chain with three disulfide bridges, was cloned, expressed and crystallized in a monoclonic form, space group P2(1), with a = 25.7 A, b = 38.2 A, c = 28.8 A and beta = 109 degrees. The structure was resolved by molecular replacement, using Alzheimer's protein precursor inhibitor and bovine pancreatic trypsin inhibitor three-dimensional structures as search models. The molecule with one sulfate ion and 43 associated water molecules was refined by XPLOR to an R-factor of 18.9% at 1.6 A. The molecule was not degraded by trypsin and did not inhibit trypsin or tested serine proteases. As opposed to the other Kunitz family members, C5 demonstrates left-handed chirality of the Cys14-Cys38 disulfide bond. Inversion of the Thr13 carbonyl and bulky side-chains at the interface with trypsin in a model of the C5-trypsin complex may explain the lack of inhibition of trypsin.

The analgesic effect of a popliteal plexus blockade after total knee arthroplasty: A feasibility study

INTRODUCTION

An obturator nerve block (ONB) and a femoral triangle block (FTB) provide effective analgesia after total knee arthroplasty (TKA) without impeding the ambulation, although the ONB produces motor blockade of the hip adductor muscles. The popliteal plexus (PP) in the popliteal fossa is formed by contribution from the tibial nerve and the posterior obturator nerve, innervating intraarticular genicular structures and the posterior capsule of the knee. We hypothesised that a popliteal plexus block (PPB) as a supplement to an FTB would reduce pain after TKA without anaesthetising motor branches from the sciatic nerve in the popliteal fossa.

AIM

To assess the analgesic effect of adding a PPB to an FTB in 10 subjects with significant pain after TKA.

METHODS

All subjects underwent unilateral TKA with spinal anaesthesia and received an FTB. The cutaneous sensation and the postoperative pain were assessed. The primary outcome was the proportion of subjects with pain above numeric rating scale (NRS) 3 followed by a reduction to NRS 3 or below after conducting a PPB.

RESULTS

Ten subjects with a median pain of NRS 5.5 (interquartile range [IQR] 4-8) after unilateral TKA received a PPB. All 10 subjects experienced a reduction in pain to NRS 3 or below (NRS 1.5 [IQR 0-3]) within a mean time of 8.5 (95% CI 6.8-10.2) minutes. Three subjects were completely pain free after the PPB. The ankle muscle strength was not affected.

CONCLUSIONS

The PPB provided effective pain relief without affecting the ankle muscle strength in all 10 subjects with significant pain after TKA and an FTB.

Effect of GH/IGF-I deficiency on long-term renal changes and urinary albumin excretion in diabetic dwarf rats

Growth hormone (GH) and insulin-like growth factor I (IGF-I) may play a role in early diabetic renal and glomerular growth and in the later development of experimental diabetic kidney disease. Rats from a genetic GH/IGF-I-deficient dwarf rat strain were made streptozotocin diabetic and were compared with nondiabetic dwarf rats. GH/IGF-I-intact rats with and without diabetes served as controls. After 6 mo of diabetes, kidney weight and total glomerular volume increased significantly in GH/IGF-I-intact diabetic rats compared with the nondiabetic GH/IGF-I-intact rats (P < 0.05), whereas the diabetic dwarf rats had insignificant changes compared with dwarf control rats. By the end of the study, urinary albumin excretion (UAE) increased from similar base levels of approximately 15-20 micrograms/24 h to 473 +/- 52 (SE) micrograms/24 h in GH/IGF-I-intact diabetic rats compared with 151 +/- 32 micrograms/24 h in diabetic dwarf rats (P < 0.01). In conclusion, isolated GH/IGF-I deficiency reduces the degree of renal and glomerular hypertrophy and the increase in UAE after 6 mo of experimental diabetes in GH/IGF-I-deficient rats.

Inhibition of renal ornithine decarboxylase activity fails to reduce kidney size and urinary albumin excretion in diabetic rats with manifest kidney hypertrophy

Formation of polyamines has previously been shown to play an important role for initial kidney growth in experimental diabetes, as treatment of diabetic rats with a selective ornithine decarboxylase (ODC) inhibitor, initiated immediately after diabetes induction, abolishes the initial kidney growth. In order to investigate the role of polyamine formation for the maintenance of diabetic kidney hypertrophy, ODC inhibition was initiated after manifest kidney hypertrophy had occurred. The kidney weight in diabetic rats was significantly larger than in control rats after a diabetes duration of 7, 14, 50 and 71 days and the total glomerular volume was increased in kidneys from diabetic rats after a diabetes duration of 71 days. Renal activity of ODC was increased in diabetic rats throughout the study period of 71 days. Treatment of diabetic rats with the selective ODC inhibitor di-fluoro-methyl-ornithine (DFMO) was maintained for two periods (days 7-14 and days 50-71). DFMO treatment had no effect on 24-h food consumption, blood glucose concentration or body weight. However, despite almost total inhibition of the kidney ODC activity, there was no effect on kidney growth or total glomerular volume in the DFMO treated diabetic rats compared to placebo treated diabetic rats. Finally, the urinary albumin excretion was markedly increased in diabetic rats with no effects of ODC-inhibition. In conclusion, inhibition of ODC initiated in diabetic rats with manifest kidney enlargement had no effect on renal size, glomerular volume or urinary albumin excretion. These findings together with our previous findings indicate that the role of polyamines in diabetic kidney enlargement is restricted to the first week after diabetes induction.

Elucidation of the origin of multiple conformations of the human alpha 3-chain type VI collagen C-terminal Kunitz domain: the reorientation of the Trp21 ring

The human alpha 3-chain type VI collagen C-terminal Kunitz domain fragment (alpha 3(VI)) has been studied by two dimensional 1H-1H and 1H-13C NMR spectroscopy at 303 K. It is shown that the secondary structure of the protein is strikingly similar to that of BPTI, and a number of unusual H alpha chemical shifts, which are highly conserved in Kunitz-domain proteins, are also observed for a alpha 3(VI). Furthermore, a series of exchange cross peaks observed in 1H-1H spectra shows that a large number of protons in the central beta-sheet exist in two different chemical environments, corresponding to two unequally populated conformations that are slowly exchanging on the NMR time scale. Several protons, including Ser47(53) H alpha, Arg32(28) H(gamma 1) and H(gamma 2), and GLN48(54) H(beta 2), all located in the vicinity of the Trp21(27) ring in the crystal structure of alpha 3(VI) [Arnoux, B. et al. (1995) J. Mol. Biol., 246, 609-617], have very different chemical shifts in the two conformations, the most affected being Gln48(54) H(beta 2) (delta sigma = 3 ppm), which is placed directly above the Trp21(27) ring in the crystal structure of alpha 3(VI). It should be concluded that the origin of the multiple conformations of the central beta-sheet is a reorientation of the Trp21(27) ring. From the intensities of corresponding signals in the two conformations, the populations, the population of the minor conformation was found to be 6.4 +/- 0.2% of that of the major conformation, while a rate constant kM = 1.01 +/- 0.05 s-1 for the major to minor interconversion was obtained from a series of NOESY spectra with different mixing times. In addition, it is shown that Cys14(20)-Cys38(44) disulfide bond isomerization, previously observed in BPTI [Otting, G. et al. (1993) Biochemistry, 32, 3571-3582], is also likely to occur in alpha 3(VI).

13C NMR, X-ray, and differential scanning calorimetry investigations of truncated BPTI (aprotinin) analogues

Truncated BPTI missing residues 1 and 2 is investigated together with variants thereof (Lys-15, Arg-17, and Arg-42 are replaced by other residues in various combinations). A comparison of the X-ray structure of BPTI with that of 3-58BPTI(K15R,R17A,R42S) shows only minor variations for the backbone, but the lack of salt bridge between the terminals and the lack of two N-terminal residues provide a structure open at one end. Comparisons of amide exchange rates show a dramatic increase for the most slowly exchanging NH protons of 3-58BPTI and the analogues thereof, as compared to those of the wild-type despite only small differences in the structures. The amide exchange rates for truncated analogues increase with decreasing TTEP (temperature top endothermic peak) values. On the basis of the known structural changes comparisons to 13C chemical shifts are made. 13C chemical shifts are assigned using the D-isotope and HMBC techniques. Excellent resolution is obtained in these 1D natural abundance spectra. 13C NMR chemical shifts are shown to be able to gauge structural changes. A comparison of 13C chemical shifts of WT BPTI (aprotinin) and 3-58BPTI reveals effects caused by (i) the removal of the salt bridge of the terminii, (ii) the charge of the N-terminus, and (iii) the increased mobility of the side chain of Tyr-23. Small effects are also seen due to a conformational change of the aromatic ring of Phe-4. Ring current shifts at 13C chemical shifts are calculated. The difference in the calculated ring current effects are small comparing the wild-type with 3-58BPTI(K15R,R17A,R42S) provided the structures are relaxed. Protein unfolding as a function of pH and temperature is studied by DSC. Unfolding occurs at lower temperature with N-terminally truncated analogues, and the maximum is shifted toward higher pH.

Patient-reported lymphedema after sentinel lymph node mapping in women with low-grade endometrial cancer

BACKGROUND

Sentinel lymph node mapping is a minimally invasive surgical staging procedure that allows identification of macro- and micrometastases. The implementation of sentinel lymph node mapping to women with low-grade endometrial cancer allows detection of lymph node metastases and avoids the morbidity of radical pelvic lymphadenectomy. The extent of myometrial invasion is highly predictive of lymph node metastases but is hard to determine precisely preoperatively. The exact rate of lymph node metastases in the large group of women with <50% myometrial invasion is low but unknown. The benefit of detecting metastases in this group should balance the risk of lymphedema. There is limited knowledge of early and late lymphedema and its impact on the quality of life in women with low-grade endometrial cancer following sentinel lymph node mapping.

OBJECTIVE

The primary objective was to investigate the risk of patient-reported lymphedema after sentinel lymph node mapping in women with low-grade endometrial cancer. In addition, we aimed to evaluate risk factors for lymphedema and the condition-specific quality of life (QoL) among women who reported lymphedema 12 months after surgery.

STUDY DESIGN

Women with presumed stage I low-grade endometrial cancer were included in a national prospective cohort study on sentinel lymph node mapping from March 2017 to February 2022. Women completed a package of validated patient-reported outcome measures before surgery, 3 and 12 months after surgery. The primary outcome was the leg lymphedema domain score from the European Organisation for Research and Treatment of Cancer-Endometrial Cancer Module (EORTC QLQ-EN24). The lymphedema assessment was further supplemented by 7 validated single items from the European Organisation for Research and Treatment of Cancer item library addressing lymphedema of legs, genitals, and groin. The disease-specific quality of life was assessed using the validated Lymphedema Quality of Life Tool. Scores were linearly transformed to 0 to 100. A change from baseline of 8 points in leg lymphedema sum-score was considered clinically important. Mean difference scores over time with 95% confidence interval were estimated. Multiple linear regression models evaluated baseline predictors associated with the 12 months postoperative lymphedema score, and if early lymphedema predicted lymphedema at 12 months after surgery. Lymphedema condition-specific quality of life was evaluated for women with lymphedema.

RESULTS

Seventy-nine % (486/617) completed patient-reported outcome measures at baseline and 12 months. The mean difference score of leg lymphedema from baseline to 12 months was 5.0, confidence interval [3.3, 6.8], that is, below the threshold for clinical importance. Baseline leg lymphedema score and body mass index were positively associated with the leg lymphedema score at 12 months. The leg lymphedema score at 3 months was associated with a higher 12-month score. High scores of lymphedema at 12 months were negatively associated with the women's daily activities, appearance, emotional functioning, and global quality of life and increased their subjective symptom burden.

CONCLUSION

Women with low-grade endometrial cancer have a low risk of lymphedema after sentinel lymph node mapping. Leg swelling at baseline and body mass index predicted more lymphedema at 12 months after surgery. Early lymphedema at 3 months predicted persistent lymphedema. A high leg lymphedema score at 12 months is associated with impairment in several aspects of quality of life.