Role of tesmin expression in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most commonly diagnosed cancer and the most frequent cause of cancer-associated mortality worldwide. Tesmin (MTL5) is a 60 kDa protein which has cysteine rich motifs, characteristic of metallothioneins. Tesmin expression was first observed in germ cells during spermatogenesis. Increased tesmin expression in NSCLC has been described previously. Minichromosome maintenance proteins (MCMs) serve a critical role in replication and cell cycle progression, i.e. in NSCLC. The aim of the present study was to evaluate the localization and intensity of tesmin, MCM5 and MCM7 protein expression in NSCLC and their association with the clinicopathological data of patients. Archival paraffin blocks of 243 cases of NSCLC and 104 non-cancerous tissue samples from the surgical margin (control) were obtained from patients treated at the Clinic of Thoracic Surgery of Wroclaw Medical University (Wroclaw, Poland) between 2010 and 2016, and were used for tissue microarrays and immunohistochemical (IHC) experiments. Laser capture microdissection was used for the isolation of cancer cells from 36 frozen samples of NSCLC and 8 control samples, and subsequently, MTL5, MCM5 and MCM7 mRNA expression was detected separately by reverse transcription-quantitative PCR. Positive cytoplasmic and nuclear tesmin, as well as nuclear MCM5 and MCM7 IHC expression were observed in 95.1, 83.67, 95.51 and 100% of the NSCLC cases, respectively. MTL5, MCM5 and MCM7 mRNA expression was observed in 91.66% of the cancer cases for all genes. The statistical analysis revealed increased tesmin IHC expression in cancer cells compared with the control. A positive correlation was observed between the IHC expression of nuclear tesmin and MCM5 proteins (r=0.33; P<0.0001) and nuclear tesmin and MCM7 proteins (r=0.315; P<0.0001). In addition, a positive correlation between the mRNA expression levels of MTL5 and MCM5 (r=0.421; P<0.05), MTL5 and MCM7 (r=0.557; P<0.01) was demonstrated. The survival analysis revealed that the presence of IHC cytoplasmic tesmin expression was a positive prognostic marker in NSCLC (P=0.0524). Furthermore, in vitro experiments performed on the NCI-H1703 cell line revealed that silencing of MTL5 mRNA and tesmin caused the downregulation of the expression levels of MCM5 and MCM7 and decreased the number of cells in the G2 phase. A positive association among tesmin, MCM5 and MCM7 could indicate a possible role of tesmin in the proliferation of NSCLC cancer cells.

Expression of tesmin (MTL5) in non‑small cell lung cancer: A preliminary study

Lung cancer is the most commonly diagnosed cancer and the most frequent cause of death worldwide. Tesmin (testis‑specific metallothionein‑like protein; MTL‑5) is a 60‑kDa protein which has cysteine‑rich motifs (CXC domain), characteristic of metallothioneins (MTs). Tesmin expression has been observed in germ cells during spermatogenesis, oogenesis and also in various cell nuclei after exposure to heavy metal ions. Yet, the role of tesmin in carcinogenesis is unknown. The aim of the present study was to evaluate the localization and intensity of tesmin expression in non‑small cell lung cancer (NSCLC) and its association with the clinicopathological data of patients. A total of 121 cases of NSCLC and 20 cases of non‑cancerous tissue samples from the surgical margin (control) were used for immunohistochemistry (IHC). In addition, 20 cases of frozen NSCLC tissues and 20 cases of control were used for the in vivo study. Normal lung fibroblasts (IMR‑90) and lung cancer cell lines NCI‑H1703 (lung squamous cell carcinoma), NCI‑H522 and A549 (both adenocarcinomas of the lung) were used for western blot analysis (WB) and RT‑PCR studies. Positive cytoplasmic tesmin expression was observed in 88.42% of the examined cases of NSCLC. Statistical analysis showed increased IHC tesmin expression in cancer cells compared to that noted in the controls. In addition, MTL5 mRNA and WB tesmin protein expression were also higher in cancer cases compared to the controls. A positive correlation between tesmin and Ki‑67 IHC expression was demonstrated (r=0.32; P<0.001). Higher WB tesmin expression was also associated with shorter overall survival (P<0.05, Mantel‑Cox test). The in vitro study revealed higher tesmin protein (WB) and MTL5 (qPCR) in lung cancer cell lines compared to the lung fibroblast control cell line. Higher tesmin expression in cancer cells compared to control cells may suggest a role of tesmin in NSCLC carcinogenesis. A positive correlation between tesmin and Ki‑67 could indicate a possible role of tesmin in the proliferation of NSCLC.

Metallothionein Isoform Expression in Benign and Malignant Thyroid Lesions

BACKGROUND

Metallothioneins (MTs) are involved in numerous cell processes such as binding and transport of zinc and copper ions, differentiation, proliferation and apoptosis, therefore contributing to carcinogenesis. Scarce data exist on their expression in benign and malignant lesions of the thyroid.

MATERIALS AND METHODS

mRNA expression of functional isoforms of MT genes (MT1A, MT1B, MT1E, MT1F, MT1G, MT1H, MT1X, MT2A, MT4) was studied in 17 nodular goiters (NG), 12 follicular adenomas (FA) and 26 papillary thyroid carcinomas (PTC).

RESULTS

One-way ANOVA revealed significant differences in mRNA expression levels of MT1A (p<0.05), MT1E (p<0.005), MT1F (p<0.0001), MT1G (p<0.005), MT1X (p<0.0005) and MT2A (p<0.005) in the analyzed samples. Post hoc analysis confirmed a significantly lower expression of MT1A mRNA in PTC compared to NG (p<0.05). Significant down-regulation was also noted for other MT isoforms in PTC in comparison to NG: MT1E (p<0.05), MT1F (p<0.0001), MT1G (p<0.005), MT1X (p<0.0005) and MT2A (p<0.05). In addition, significant down-regulation of MT1F and MT1G in FA compared to NG was observed (p<0.005 and p<0.05, respectively).

CONCLUSION

Expression of functional MT isoforms may contribute to thyroid carcinogenesis and potentially serve as a diagnostic marker in distinguishing benign and malignant lesions.

Prognostic Significance of NOGO-A/B and NOGO-B Receptor Expression in Malignant Melanoma - A Preliminary Study

BACKGROUND

Neurite outgrowth inhibitor type B (NOGO-B) and its receptor (NGBR) were shown to regulate various crucial cellular processes and may be therefore potential factors influencing carcinogenesis.

MATERIALS AND METHODS

Expression of NOGO-A, NOGO-A/B and NGBR was studied in benign melanocytic lesions and primary tumors and metastases of malignant melanoma (MM).

RESULTS

Cytoplasmic expression of the studied antigens was detected in melanocytes and MM cells. NOGO-A/B expression was significantly lower in metastatatic MM cases compared to primary MM tumors (p<0.01) and bening melanocytic lesions (p<0.001). In primary MM tumors, NOGO-A expression intensity positively correlated with NOGO-A/B (r=0.32, p<0.05) and NGBR expression (r=0.53, p<0.0001). NOGO-B and NGBR immunoreactivity correlated negatively with depth of primary MM infiltration (both p<0.01). Moreover, low NOGO-A/B expression was a factor of poor prognosis of primary MM.

CONCLUSION

NOGO-A/B may be a negative prognostic factor of MM.

Expression of EMT Markers SLUG and TWIST in Breast Cancer

BACKGROUND

The epithelial-mesenchymal transition (EMT) has been observed in progression of in situ breast cancer to the invasive form and might be initiated by snail family zinc finger 2 (SLUG) and twist family bHLH transcription factor 1 (TWIST) protein overexpression. During this phenomenon, cells lose their epithelial phenotype and acquire mesenchymal features. The aim of the study was to examine the association of EMT markers SLUG and TWIST with clinicopathological data and the possibility of using these proteins as prognostic markers of breast cancer.

MATERIALS AND METHODS

Immunohistochemical analysis (IHC) of SLUG and TWIST expression was performed on archival paraffin samples of 19 cases with fibrocystic breast changes (control group), 148 cases of invasive ductal breast cancer (IDC) and 26 of invasive lobular breast cancer (ILC). Laser capture microdissection for isolation of cells from 17 frozen samples of IDC was employed and subsequently SLUG and TWIST mRNA expression in cancer and stromal cells was detected separately by real-time polymerase chain reaction.

RESULTS

SLUG and TWIST expression in IDC was significant higher in stromal cells regardless of the method of quantification used (p<0.001 for SLUG mRNA, and p<0.0001 for SLUG IHC, TWIST IHC and TWIST mRNA expression). Positive correlation of SLUG and TWIST protein and mRNA expression was observed in stromal cells of IDC (r=0.347; p<0.0001 and r=0.704; p<0.01, respectively). Expression of TWIST protein in IDC was higher in cancer cells of cases with shorter event-free survival period, as well as in stromal cells of cases with shorter overall survival period (p<0.05 for both).

CONCLUSION

Stromal cells could play a role in the regulation of EMT in breast cancer.

The effect of physical training on the N-methyl-N-nitrosourea-induced mammary carcinogenesis of Sprague-Dawley rats

The impact of physical activity on carcinogenesis has been demonstrated in many studies. Taking into account the discrepant results of physical exercise on the cell proliferation and apoptosis of breast cancer, we aimed to examine the impact of physical training on N-methyl-N-nitrosourea-(MNU)-induced mammary carcinogenesis. Fifty female rats were divided into four groups according to the intensity of physical activity they undertook. The number of developed tumors, tumor volume, and histopathological diagnoses were noted. Apoptosis and cell proliferation were studied by the number of TUNEL-positive and Ki-67-expressing cells. We demonstrated a statistically significant decrease in the tumor number between all trained groups and the control group. The results were most pronounced in the group with a moderate intensity of training. Moreover, we showed a decrease in tumor volume as training intensity increased, though the differences were not statistically significant. The mean number of TUNEL-positive cancer cells was significantly higher in the training groups than in the control group. These data suggest that physical training, especially of moderate intensity, may alleviate MNU-induced mammary carcinogenesis. The results could suggest that physical exercise-induced apoptosis may be a protective mechanism.

Metallothionein-3 Increases Triple-Negative Breast Cancer Cell Invasiveness via Induction of Metalloproteinase Expression

It has been recently found that metallothionein-3 (MT3) enhances the invasiveness and tumorigenesis of prostate cancer cells. This finding is in contrast to those of earlier studies, which indicated that overexpression of MT3 in breast cancer and prostate cancer cell lines inhibits their growth in vitro. Therefore, to clarify the role of MT3 in breast cancer progression, we analyzed the effect of MT3-overexpression on proliferation, invasiveness, migration, and tumorigenesis of breast cancer MDA-MB-231/BO2 cells. It was found that MDA-MB-231/BO2 cells overexpressing MT3 were characterized by increased invasiveness in vitro, compared to the control cells. Interestingly, this increased invasiveness correlated with a highly increased concentration of MMP3 in the culture supernatants (p<0.0001). Our data suggest that MT3 may regulate breast cancer cell invasiveness by modulating the expression of MMP3. These experimental results, obtained using triple-negative MDA-MB-231/BO2 cells, were further supported by clinical data. It was found that, in triple-negative breast cancer (TNBC), nuclear MT3 immunoreactivity in cancer cells tended to be associated with patients' shorter disease-specific survival, suggesting that nuclear MT3 expression may be a potential marker of poor prognosis of triple-negative TNBC cases.

Massage may initiate tendon structural changes--a preliminary study

BACKGROUND

Physical exercise is now a widely known and studied factor of the proper functioning of living organisms. Many questions remain unanswered concerning various aspects of the changes in the morphology of structures subjected to chronic physical exercise.

MATERIALS AND METHODS

This study was conducted on fifty Buffalo strain rats, randomly divided into two equal (experimental and control) groups. All animals were subjected to physical training on a running track for 10 weeks, whereas only in the experimental group, massage was additionally applied five-times per week.

RESULTS

An increase in the percentage of collagen fibers in tendons with the smallest diameter (≤100 nm) was observed only in the experimental group in week 3, followed by a decrease in weeks 5 and 7. A subsequent repeated increase was observed in week 10 of the study. No significant differences were observed for either study group in the number of collagen fibers based on fiber diameter (101-200 nm, 201-300 nm and 301-400 nm).

CONCLUSION

The results of this preliminary study showed that long-term massage performed during running training may initiate for small structural changes in the rat tendon. Further morphological studies with prolonged observation periods are recommended.

Nogo-B receptor expression correlates negatively with malignancy grade and ki-67 antigen expression in invasive ductal breast carcinoma

BACKGROUND

Nogo-B receptor (NgBR) has been shown to be involved in endothelial cell chemotaxis and morphogenesis. However, few studies analyzing its expression in cancer cells have been performed.

MATERIALS AND METHODS

We examined NgBR expression in 233 patients with invasive ductal breast carcinoma (IDC) and corresponding non-malignant breast tissues (NMBT) on mRNA (real-time polymerase chain reaction) and protein levels (immunohistochemistry; IHC and western-blot analysis). NgBR expression was found also analyzed in breast cancer cell lines of varying invasiveness.

RESULTS

NgBR expression was increased in IDC compared to NMBT on the mRNA (p=0.0007) and protein level (p=0.018). NgBR expression decreased significantly with IDC malignancy grade and correlated negatively with the Ki-67 antigen expression (r=-0.18; p=0.0005). High NgBR mRNA expression was associated with estrogen receptor negativity (p=0.0023) and the triple-negative phenotype of the tumors (p=0.0129).

CONCLUSION

NgBR may be involved in IDC development, however, its role in its progression requires further research.

Expression of Nogo isoforms and Nogo-B receptor (NgBR) in non-small cell lung carcinomas

BACKGROUND

Nogo-B was recently shown to be involved in proliferation, apoptosis and invasiveness of cancer cells, whereas its specific receptor (NgBR) was found to be up-regulated in estrogen receptor-α positive breast cancer. No data are currently available concerning their expression in non-small cell lung carcinomas (NSCLC).

MATERIALS AND METHODS

Expression of Nogo isoforms and NgBR was studied in 191 NSCLC.

RESULTS

Higher Nogo-A/B immunoreactivity was noted in cancer cells of squamous cell carcinomas (SQC) compared to adenocarcinomas (p<0.001). Stage II-IV tumors had the lowest Nogo-A/B expression (p<0.0001) compared to stage I cases. Nogo-A/B expression decreased with increasing SQC malignancy grade (p=0.026). Significant NgBR mRNA down-regulation was associated with larger primary tumor size (p=0.039), lymph node involvement (p=0.039) and advancement stage (p=0.0054). Low NgBR mRNA expression predicted poor patients outcome (p=0.029).

CONCLUSION

The current data may point to the involvement of Nogo isoforms and NgBR in the pathogenesis of NSCLC.

Comparison of minichromosome maintenance proteins (MCM-3, MCM-7) and metallothioneins (MT-I/II, MT-III) expression in relation to clinicopathological data in ovarian cancer

BACKGROUND

Despite great progress in the understanding of ovarian cancer biology, clinicopathological data (i.e. grade, stage, histological type and residual disease after surgery) seem to be the most important prognostic factors.

MATERIALS AND METHODS

The present study aimed to investigate the relationship between expression of minichromosome maintenance proteins (MCM-3, MCM-7), metallothioneins (MT-I/II, MT-III), and Ki-67 in 103 ovarian cancer cases, mostly of the serous histological type.

RESULTS

Statistical analysis revealed strong positive correlations in the expression of MCM-3 vs. Ki-67 (r=0.492), MCM-7 vs. Ki-67 (r=0.651), and MCM-3 vs. MCM-7 (r=0.515) (all p<0.0001). The Kruskal-Wallis test showed an association of increased expression of MCM-3 and Ki-67 with increasing grade of histological malignancy (p=0.0011, p=0.029, respectively). Regarding clinical progression, cytoplasmic MT-I/II expression was significantly higher in more advanced disease stages (III+IV vs. I+II; p=0.0247).

CONCLUSION

Due to the correlations shown here, the determination of MCM proteins as proliferation markers of ovarian cancer, should be strongly considered.

Immunohistochemical characterization of N-methyl-N-nitrosourea-induced mammary tumours of Sprague-Dawley rats

BACKGROUND

Single dose of N-methyl-N-nitrosourea (MNU) was shown to induce malignant tumours in susceptible rat strains. However, such tumours are not well-characterized.

MATERIAL AND METHODS

We characterized MNU-induced tumours in Sprague-Dawley rats using ultrasonographic, radiographic and immunohistochemical (IHC) methods.

RESULTS

In 27 rats, 41 tumours developed, appearing ultrasonographically as hypodense, non-homogenic areas with signal enhancement at their periphery. Out of these, 39 were of malignant epithelial origin, with an IHC phenotype closely-resembling that of human invasive ductal breast carcinoma. One case was diagnosed as carcinosarcoma. IHC analysis revealed that Ki-67 antigen expression correlated positively with tumour volume (r=0.40, p=0.0079). Moreover, tumours with α-smooth muscle actin in the tumour stroma were characterized by a higher proliferative rate as compared to those without its expression (p<0.05).

CONCLUSION

This rat model of chemical carcinogenesis may be suitable for examining breast cancer development and progression.

Podoplanin expression in cancer-associated fibroblasts correlates with VEGF-C expression in cancer cells of invasive ductal breast carcinoma

Podoplanin (D2-40) was shown to be expressed in cancer-associated fibroblasts (CAFs) of various malignancies. The study aimed at examining its impact on angiogenesis and lymphangiogenesis markers in invasive ductal carcinoma of the breast (IDC). The studies were performed on 104 archival cases of IDC using immunohistochemical technique. Podoplanin expression in CAFs correlated positively with cancer cell VEGF-C expression (r=0.19, p=0.0495) and intratumoral microvessel count (MVC) of CD31 positive vessels (r=0.30, p=0.0018), whereas negative correlations were observed with peritumoral MVC of D2-40 and Lyve-1 positive lymphatic vessels (r=-0.26, p=0.008 and r=-0.27, p=0.0058, respectively). Podoplanin expression in CAFs did not correlate with VEGF-A and VEGF-D expression in cancer cells, nor exerted any prognostic significance. Podoplanin expression in CAFs may have impact on angio- and lymphangiogenesis processes in IDC.

Impact of SOX18 expression in cancer cells and vessels on the outcome of invasive ductal breast carcinoma

PURPOSE

SOX18 is a transcription factor known to be involved in hair follicle, blood and lymphatic vessel development, as well as wound healing processes (together with SOX7 and SOX17). In addition, it has been reported that SOX18 may affect the growth of cancer cells in vitro. Until now, the exact role of SOX18 expression in invasive ductal breast carcinoma (IDC) has remained unknown.

METHODS

In this study, we have investigated SOX18 expression in cancer cells and endothelial cells in 122 IDC samples using immunohistochemistry (IHC). SOX18 expression was also determined using real-time PCR and Western blotting in a series of breast cancer-derived cell lines (i.e., MCF-7, BT-474, SK-BR-3, MDA-MB-231, BO2).

RESULTS

Using IHC, we observed SOX18 nuclear expression in cancer cells, as well as in blood and lymphatic vessels of the IDC samples tested. SOX18 expression in the IDC samples correlated with a higher malignancy grade (Grade 2 and Grade 3 versus Grade 1; p = 0.02 and p = 0.009, respectively) and VEGF-D expression (r = 0.27, p = 0.007). SOX18 expression was also associated with HER2 positivity (p = 0.02). A significantly higher SOX18 expression was found in the HER2-positive cell line BT-474, and a significantly lower expression in the triple negative cell lines MDA-MB-231 and BO2. Laser capture microdissection of IDC samples revealed significantly higher mRNA SOX7, SOX17 and SOX18 expression levels in the vessels as compared to the cancer cells (p = 0.02 and p = 0.0002, p < 0.0001, respectively). SOX18 positive intratumoral and peritumoral microvessel counts (MVC) were associated with higher malignancy grades (p = 0.04 and p = 0.02, respectively). Moreover, peritumoral SOX18 positive MVC were found to act as an independent marker for a poor prognosis (p = 0.04).

CONCLUSION

SOX18 expression may serve as a marker for a poor prognosis in IDC.

Hsp-27 expression in invasive ductal breast carcinoma

The aim of this study was to determine the intensity of Hsp27 protein expression in fibrocystic breast changes (FC) and invasive ductal breast carcinoma (IDC) and to examine its impact on patients' clinico-pathological characteristics and overall survival. Immunohistochemical reactions were conducted on archival samples of 20 cases of FC and 101 cases of IDC treated in 1999-2002. Nuclear-cytoplasmic Hsp27 expression was observed in 92 (92.1%) of the examined cases of IDC, and all the cases of FC. Significantly higher Hsp27 expression was observed in G2 (p < 0.01) and G3 cases (p < 0.0001) compared to FC. HER-2 positive cases had higher Hsp27 expression (p = 0.0153), than HER-2 negative cases. Our research showed that Hsp27 could have an impact on tumor malignancy. Moreover, a positive correlation between the expression of Hsp27 and HER-2 positive cases was demonstrated.

Significance of podoplanin expression in cancer-associated fibroblasts: a comprehensive review

Cancer-associated fibroblasts (CAFs) are well-known to be part of the tumor microenvironment. This heterogeneous population of cells of the tumor microenvironment via secretion of various growth factors and cytokines was shown to contribute to increased cancer cell proliferation rate, migration, invasiveness and other key processes such as angiogenesis and lymphangiogenesis. Recent studies identified podoplanin as a marker of CAFs in various malignancies and its expression in these cells was shown to influence cancer progression. In some studies it yielded a prognostic impact on patient survival which was strongly dependent on the entity of the tumor. This review summarizes recent findings concerning the biology of podoplanin in cancer progression with particular emphasis on its expression in CAFs.

Expression of melatonin receptor MT1 in cells of human invasive ductal breast carcinoma

In humans, two main types of membrane melatonin receptors have been identified, MT1 and MT2. Expression of MT1 in neoplastic cells seems to increase the efficacy of melatonin's oncostatic activity. The purpose of this study was to determine the distribution and the intensity of MT1 expression in breast cancer cells and to correlate it with clinicopathological factors. Immunohistochemical studies (IHC) were conducted on 190 cases of invasive ductal breast carcinomas (IDC) and molecular studies were performed on 29 cases of frozen tumor fragments and selected breast cancer cell lines. Most of the studied tumors manifested a membranous/cytoplasmic IHC expression of MT1. In IDC, the MT1 expression was higher than in fibrocystic breast disease. MT1 expression was higher in estrogen receptor positive (ER+) and HER2 positive (HER2+) tumors. Triple negative tumors (TN) manifested the lowest MT1 expression level. The lowest MT1 protein expression level was noted in the TN breast cancer cell line MDA-MB-231 compared with ER+ cell lines MCF-7 and SK-BR-3. MT1 mRNA expression was negatively correlated with the malignancy grade of the studied IDC cases. Moreover, higher MT1 expression was associated with patients' longer overall survival (OS) in the group of ER+ breast cancers and treated with tamoxifen. Multivariate analysis indicated that MT1 was an independent prognostic factor in the ER+ tumors for OS and event-free survival in the ER+ tumors. The results of this study may point to a potential prognostic and therapeutic significance of MT1 in IDC.

Impact of different tumour stroma assessment methods regarding podoplanin expression on clinical outcome in patients with invasive ductal breast carcinoma

BACKGROUND

Podoplanin, a small mucin-type transmembrane protein has been shown in several studies to be expressed in cancer-associated fibroblasts (CAFs) and affect patient outcome.

MATERIALS AND METHODS

We evaluated podoplanin expression in CAFs in a cohort of 257 patients with invasive ductal breast carcinomas (IDCs) using three different assessment scales based on the number of positive cells alone or in combination with the reaction intensity.

RESULTS

Two of the utilized scales yielded prognostic information concerning patients' overall survival (OS), but scores were not independent prognostic factors in the multivariate analysis. On the contrary, two scales based on the combination of cell positivity and reaction intensity had no significant impact on patients' OS, but they were significantly correlated with a greater number of analysed clinicopathological parameters.

CONCLUSION

In summary, podoplanin expression in CAFs may be considered a possible marker of poor prognosis in IDC, however, caution should be taken as the results varied regarding the utilized scales.

Expression of metallothionein-III in patients with non-small cell lung cancer

BACKGROUND

Currently, there is little knowledge concerning expression of metallothionein-III (MT-III), also known as growth-inhibitory factor, in non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

In this study, we evaluated MT-III expression in 184 patients using immunohistochemistry and in 61 cases using real-time polymerase chain reaction.

RESULTS

MT-III mRNA expression was significantly higher in NSCLC as compared to non-malignant lung tissues (NMLT; p<0.0086). MT-III expression was noted in the cytoplasm and nucleus of cancer cells. Significantly lower nuclear MT-III (p<0.0001) expression and significantly higher cytoplasmic MT-III (p=0.0068) expression was noted in the pneumocytes of NMLT, as compared to NSCLC. Nuclear MT-III expression was significantly higher in G1 cases as compared to G2 (p=0.0308) and G3 (p=0.0194) cases. Low cytoplasmic MT-III expression was associated with larger primary tumour size (p=0.0378). Lower MT-III mRNA and cytoplasmic MT-III expression was associated with poor patient outcome (p=0.0410 and p=0.0347, respectively).

CONCLUSION

MT-III expression may have an impact on the pathogenesis of NSCLC.

Role of metallothioneins in benign and malignant thyroid lesions

Recent findings in the past two decades have brought many insights into the biology of thyroid benign and malignant lesions, in particular the papillary and follicular thyroid cancers. Although, much progress have been made, thyroid cancers still pose diagnostic problems regarding differentiation of follicular lesions in relation to their aggressiveness and the treatment of advanced and undifferentiated thyroid cancers. Metallothioneins (MTs) were shown to induce cancer cells proliferation, mediate resistance to apoptosis, certain chemotherapeutics and radiotherapy. Therefore, MTs may be of utility in diagnosis and management of patients with benign and malignant lesions of the thyroid.

Metallothionein 1F and 2A overexpression predicts poor outcome of non-small cell lung cancer patients

Metallothioneins (MT) are intracellular, low molecular weight proteins (6-7 kDa) involved in binding of metal ions, scavenging of free radicals, cell proliferation and apoptosis and resistance to certain chemotherapeutics. Four basic families of MT proteins are distinguished: MT-I, MT-II, MT-III, MT-IV, within each of them different isoforms occur. The study aimed at examining the expression level of nine MT isoforms: MT-1A, -1B, -1E, -1F, -1G, -1H, -1X, MT-2A and MT-IV by using real-time PCR and MT-I/II expression by immunohistochemical (IHC) technique in 69 cases of non-small cell lung cancer (NSCLC) and 12 non-malignant lung tissues (NMLT) and to correlate them with patients clinicopathological data and Ki-67 antigen expression. Out of all the analyzed cases, 62 (89.9%) demonstrated an increased MT-I/II expression. MT-1B, 1F, -1G, -1H and MT-1X were significantly up-regulated, whereas MT-1E was significantly down-regulated in NSCLC as compared to NMLT. Only in two cases MT-IV mRNA expression was noted. Significant positive correlations were observed between each particular MT isoform expressions. Higher MT-1F and MT-1A mRNA expression was associated with larger primary tumor size (P=0.0362 and P<0.0001, respectively). Moreover, up-regulated MT-1F mRNA expression was associated with higher grade of malignancy of NSCLC (P=0.0085). Higher MT-1B mRNA expression was associated with squamocellular and adenocarcinoma subtype of NSCLC (P=0.0358). Univariate analysis showed, that up-regulated MT-1F and MT-2A mRNA predicted poor patients' survival (P=0.0206 and P=0.0097, respectively). The levels of MT-1F and MT-2A mRNA could be considered as new markers of poor prognosis of NSCLC patients.

Expression of metallothionein I/II and Ki-67 antigen in various histological types of basal cell carcinoma

Basal cell carcinoma (BCC) is the most frequent skin cancer, with many different histological subtypes. Recent studies have investigated the expression of proliferative markers, but little is known about the expression of metallothioneins (MT) in different histological subtypes of this cancer and their impact on proliferation intensity in BCC. In this study, we examined MT-I/II expression by immunohistochemistry in 58 different histological subtypes of BCC (38 nodular, six adenoid, eight infiltrative, and six metatypic cases) and correlated its expression with tumor size and Ki-67 proliferation rate. Statistical analysis revealed no significant differences in the expression of studied markers in regard to the histological subtype. A positive correlation between MT and Ki-67 expression was observed for all the studied cases (r = 0.26; p = 0.049), but was even stronger in the metatypic subtype of BCC (r = 0.85; p = 0.033). MT and Ki-67 expression did not correlate with tumor size. In conclusion, it seems that metallothioneins may have an impact on the proliferation rate of BCC,but further studies are required to determine whether MT may be a risk factor of recurrences.

Angiotensin II type 1 receptor (AT-1R) expression correlates with VEGF-A and VEGF-D expression in invasive ductal breast cancer

Recent studies point to the involvement of angiotensin II (Ang II) receptor type 1 (AT-1R) on processes of metastasing, stimulation of invasiveness and angiogenesis in tumours. In this study, the correlation between intensity of AT-1R expression and expression of lymph- and angiogenesis markers in invasive ductal breast cancers (IDC) was examined. Immunohistochemical studies (IHC) were performed on archival material of 102 IDC cases. Only 28 (27.5%) cases manifested low AT-1R expression while 74 (72.5%) cases demonstrated a moderate or pronounced AT-1R expression. Expression intensity of AT-1R was found to correlate with expressions of VEGF-A (r = 0.26; p = 0.008) and VEGF-D (r = 0.24; p = 0.015). Out of the examined markers of angiogenesis and lymphangiogenesis only the pronounced expression of VEGF-C was found to correlate with patient poor clinical outcome (p = 0.009). The positive correlation between AT-1R and VEGF-A and VEGF-D could point to stimulatory action of Ang II on their expression what might result in augmented lymph- and angiogenesis in IDC.

MUC1 in human and murine mammary carcinoma cells decreases the expression of core 2 β1,6-N-acetylglucosaminyltransferase and β-galactoside α2,3-sialyltransferase

A good correlation between the expression of mucin1 (MUC1) and T antigen was found in breast cancer tumors and breast cancer cell lines, especially after treatment with neuraminidase. The association between the appearance of T antigen and the overexpression of MUC1 was further confirmed by transfecting MDA-MB-231 cells and murine 4T1 mammary carcinoma cells with cDNA for MUC1 and using an RNAi approach to inhibit the expression of MUC1 gene in T47D cells. Furthermore, we discovered that in 4T1 cells which express the sialyl Le(X) antigen, overexpression of MUC1 caused not only appearance of T antigen, but also loss of the sialyl Le(X) structure. As the observed changes in O-glycan synthesis can be associated with changes in the expression of specific glycosyltransferases, core 1 β1,3-galactosyltransferase, core 2 β1,6-N-acetylglucosaminyltransferase (C2GnT1) and β-galactoside α2,3-sialyltransferase (ST3Gal I), we studied their expression in parental, vector-transfected and MUC1-transfected MDA-MB-231 and 4T1 cells as well as T47D cells transduced with small hairpin RNA targeted MUC1 mRNA. It was found that the expression of C2GnT1 and ST3Gal I is highly decreased in MUC1-expressing MDA-MB-231 and 4T1 cells and increased in T47D cells with suppressed expression of MUC1. Therefore, we found that changes in the structure of O-linked oligosaccharides, resulting in the occurrence of T antigen, are at least partially associated with MUC1 overexpression which down-regulates the expression of C2GnT1 and ST3Gal I. We showed also that the overexpression of MUC1 in 4T1 cells changes their adhesive properties, as MUC1-expressing cells do not adhere to E-selectin, but bind galectin-3.

Podoplanin expression by cancer-associated fibroblasts predicts poor outcome in invasive ductal breast carcinoma

AIMS

It has recently been shown that podoplanin, a mucin-type glycoprotein, is expressed by cancer cells and cancer-associated fibroblasts (CAFs), and promotes cancer cell migration and invasiveness. The biological role of podoplanin expression in tumour stroma of invasive ductal carcinoma of the breast (IDC) has not been determined.

METHODS AND RESULTS

Podoplanin expression was analysed in 117 cases of IDC and 27 cases of fibrocystic change, as well as in breast cancer cell lines, with the use of immunohistochemistry and real-time polymerase chain reaction. In 82.1% of analysed tumours, podoplanin was found only in CAFs. Only two of 117 IDC cases (1.7%) were characterized by expression of this glycoprotein in cancer cells. None of the fibrocystic changes or stroma surrounding normal ducts showed podoplanin expression. Podoplanin-positive CAFs correlated with tumour size (P = 0.0125), grade of malignancy (P = 0.0058), lymph node metastasis (P = 0.0149), lymphovascular invasion (LVI) (P = 0.0486) and Ki67 expression in cancer cells (P = 0.0128). High-level podoplanin expression (>50% of positive stroma) in the tumour stroma was significantly associated with a negative oestrogen status (P = 0.0201). Univariate, but not multivariate, analysis showed that podoplanin expression by CAFs was associated with poor patient outcome (P = 0.0202).

CONCLUSIONS

Our results suggest that podoplanin expression by CAFs could be an unfavourable prognostic marker for IDC.

Tissue microarray technique in evaluation of proliferative activity in invasive ductal breast cancer

AIM

Investigation of the relationship between expression of Ki-67 antigen and minichromosome maintenance 2 (MCM-2) protein by using an immunohistochemical study on whole sections (WS) and sections of invasive ductal breast cancer (IDC) obtained in the tissue microarray (TMA) technique.

MATERIALS AND METHODS

Material consisted of 51 archival paraffin blocks of IDC. Tissue microarrays were composed of 0.6 mm core punches. Reactions were performed using specific antibodies (anti-Ki-67 and anti-MCM-2). Intensity of the marker expression was evaluated using computer-assisted image analysis. For statistical purposes, three different tests were used.

RESULTS

Spearman rank correlation revealed a strong positive correlation between expression of tested markers: Ki-67 (TMA) vs. Ki-67 (WS) (r=0.91, p<0.05) and MCM-2 (TMA) vs. MCM-2 (WS) (r=0.87, p<0.05). Mann Whitney U-test showed no significant differences between the two markers in both analysed techniques. Moreover, the Bland-Altman plot demonstrated a low level of bias between the analysed methods.

CONCLUSION

This study shows that TMA could have a great potential in evaluation of proliferative activity in IDC and that MCM-2 protein might be a specific and sensitive marker of cell proliferation.

Correlation between expression of metallothionein and expression of Ki-67 and MCM-2 proliferation markers in non-small cell lung cancer

BACKGROUND

Metallothioneins (MTs) are low molecular weight proteins present both in normal and neoplastic cells. They protect cells from the effects of heavy metals and from damage induced by free radicals. MT bind heavy metals, exert an anti-apoptotic effect and stimulate proliferation of neoplastic cells. The role of MTs in carcinogenesis has not been fully clarified yet. This study aimed at the evaluation of the intensity of metallothionein (MT-I/II) expression in various histological types of non-small cell lung cancer (NSCLC) and correlation of the expression intensity with clinical/pathological parameters and Ki-67 and minichromosome maintaince protein 2 (MCM-2) proliferation markers.

PATIENTS AND METHODS

The studies were performed on archival material, originating from 145 patients, 105 men and 40 women (65 adenocarcinomas, 67 squamous cell carcinomas, 13 large cell carcinomas).

RESULTS

A positive correlation was noted between expression of MT-I/II and expressions of Ki-67 (r=0.1863, p=0.0248) and MCM-2 (r=0.1766, p=0.0336) in NSCLC overall. The most pronounced expression of MT-I/II was noted in the large cell carcinomas. The expression of MT-I/II was significantly lower in the adenocarcinomas than in the squamous cell carcinomas (p=0.0028) and large cell carcinomas (p=0.0485). The expression of MT-I/II showed no differences related to individual degrees of NSCLC malignancy. Univariate analysis demonstrated no significant differences in overall survival related to the expression intensity of MT-I/II, Ki-67 or MCM-2, but the survival of the patients with high expression of MT-I/II and Ki-67 in the neoplastic cells, as compared to low expression of MT-I/II and Ki-67, was shorter (the difference approached statistical significance, p=0.067).

CONCLUSION

MT-I/II expression is evident in proliferating NSCLC neoplastic cells, pointing to the prognostic importance of parallel expression of MT-I/II and Ki-67.

Correlation of intensity of MT-I/II expression with Ki-67 and MCM-2 proteins in invasive ductal breast carcinoma

The purpose of the study was to evaluate the clinical significance of the intensity of metallothionein (MT-I/II) expression and its relationship to two different proliferation markers, Ki-67 antigen and minichromosome maintaince 2 protein (MCM-2) in 117 patients with invasive ductal breast carcinoma (IDC). A significantly higher MT-I/II expression was noted in the grade 3 (G3) carcinomas as compared to those of G1 and G2. A positive correlation was observed between the MT-I/II expression and both proliferation markers, Ki-67 (r=0.20, p=0.0343) and MCM-2 (r=0.25, p=0.0065). Also a strong positive correlation was noted between Ki-67 and MCM-2 expression (r=0.52, p<0.0001). No significant correlations were found between the analyzed markers and tumour size, lymph node metastasis, oestrogen expression (ER), progesterone receptor (PR) or human epidermal growth-factor receptor (HER-2) expression. Out of the three studied markers only the high expression of Ki-67 exhibited a negative impact on patient overall and event free survival and was an independent prognostic factor. MT-I/II and MCM-2 protein expression was not correlated with poor patient outcome, although MCM-2 expression correlated (Fisher's exact test) positively with grade of malignancy (p=0.0018) and negatively with ER (p=0.0002) and PR (p=0.0056) expression. To conclude, MT-I/II may play a key role in IDC proliferation, but is not a useful prognostic factor of this disease.

Effect of melatonin on melanoma cells subjected to UVA and UVB radiation in In vitro studies

Studies performed in vivo and in vitro have shown that exogenous melatonin (Mel) exerts oncostatic effects on melanoma cells. Although the protective effect of Mel on skin and cells exposed mainly to UVB has been documented, effects of Mel have not yet been examined on melanoma cells exposed to UVA. Our investigations aimed at examination of the effect of Mel alone (0, 10(-3), 10(-6) and 10(-9) M), and after its addition to the culture medium for 30 minutes before exposure of melanoma cells to UVA (15 J/cm(2)) or UVB (30 mJ/cm(2), 60 mJ/cm(2)). Viability of the cells was examined using the colorimetric sulphorhodamine B test. Mel added to the medium at concentrations of 10(-3)-10(-8) M was found to increase the number of melanoma cells as compared to the control (cells with no Mel) after 24 hours. Compared to exposed cells without Mel, at 10(-3) M Mel, melanoma cells exposed to 30 mJ/cm(2) UVB increased in number and at 10(-9) M increased the survival of those exposed to 60 mJ/cm(2) UVB. The cells exposed to UVA (15 J/cm(2)) were protected by Mel at 10(-6) and 10(-9) M. Physiological concentrations of Mel exerted no oncostatic effects on the BM cell line used here. In addition, the pharmacological Mel concentrations stimulated proliferation of the cells. Beyond doubt, we have confirmed that Mel represents a substance which protects cells from UVA and UVB action in in vitro experiments.

Effect of melatonin on human keratinocytes and fibroblasts subjected to UVA and UVB radiation In vitro

Skin represents one of the extrapineal sites of melatonin (Mel) synthesis. In the skin Mel plays, for example, the role of an antioxidant which scavenges and inactivates free radicals arising due to UV irradiation. Although the protective effect of Mel on skin and cells irradiated mainly with UVB has been documented, to date no comparison has been made for the effects of Mel on cells exposed to UVA. Our study aimed at evaluating the effect of Mel (0, 10(-3), 10(-6) or 10(-9) M) added to culture medium 30 minutes before exposure of keratinocytes and fibroblasts to irradiation with UVA (15 J/cm(2)) and UVB (30 mJ/cm(2), 60 mJ/cm(2)). Viability of the cells was evaluated using sulphorhodamine (SRB) colorimetric test. Mel at 10(-3) M increased the number of surviving keratinocytes and at 10(-6) M increased the number of surviving fibroblasts exposed to UVB (30 mJ/cm(2), 60 mJ/cm(2)) as compared to cells exposed only to radiation. In addition, 10(-6) M protected keratinocytes exposed to the dose of 30 mJ/cm(2). Mel at 10(-3) M exerted a protective effect on both types of cells irradiated with UVA (15 J/cm(2)). As documented by our studies, Mel protects skin cells from the action of UVA and UVB. The protective effect of different Mel concentrations might result from variable expression of melatonin receptors.

Prolonged exposure to inhaled nitric oxide transiently modifies tubular function in healthy piglets and promotes tubular apoptosis

AIM

Inhaled nitric oxide (iNO) is a selective pulmonary vasodilator. We hypothesized that those piglets exposed to prolonged iNO react with a modified renal function.

METHODS

Randomized, placebo-controlled exposure to 40 p.p.m. iNO (30 h) in piglets (n = 20). Plasma and urine were sampled during three periods (first and second 12 h periods, and finally a 6 h period). We measured urine volumes, plasma and urine electrolytes (UNa, UK, UCl), plasma creatinine and urea. We calculated creatinine clearance (Ccr), and fractional excretions of sodium and potassium (FENa, FEK) and urinary excretions of electrolytes (UENa, UEK, UECl). Haemodynamic data were recorded and renal tubular apoptosis detected.

RESULTS

For the first 12 h, certain parameters significantly increased in the iNO group (mean +/- SD): UNa (mmol L(-1)), 87.7 (+/-35.0) vs. 39.3 (+/-22.9), UCl (mmol L(-1)) 80.4 (+/-32.8) vs. 48.0 (+/-26.7), FENa (%) 2.1 (+/-0.8) vs. 0.7 (+/-0.5), FEK (%) 31.7 (+/-7.0) vs. 20.7 (+/-12.3), as well as UENa (mmol) 61.0 (+/-21.1) vs. 27.6 (+/-17.9) and UECl (mmol) 57.3 (24.5) vs. 37.6 (29.0). These changes were absent in the second and third periods of the study. Significant differences in percentage of apoptotic cell nuclei in the renal cortex and medulla were found after iNO exposure: 39% vs. 15%.

CONCLUSION

Exposure to 40 p.p.m. iNO in healthy anaesthetized piglets has a transient natriuretic effect that disappears after 12 h. We also found evidence of renal tubular apoptosis promotion after 30 h of iNO.

Expression of extracellular matrix metalloproteinase (MMP-9), E-cadherin and proliferation-associated antigen Ki-67 and their reciprocal correlation in canine mammary adenocarcinomas

BACKGROUND

The purpose of the present study was to determine the expression of the proteins related to tumour metastatic potential, including matrix metalloproteinase (MMP)-9 and E-cadherin, in correlation with the expression of proliferation-associated antigen (Ki-67) in canine mammary adenocarcinomas.

MATERIALS AND METHODS

Material for the studies was obtained during surgery from 35 dogs of various breeds, aged 7 to 16 years. Neoplastic tumours were verified by a pathologist. The studied proteins were detected by immunohistochemical reactions. The microphotographs of the studied tumours were subjected to computer-assisted image analysis using MultiScaneBase V 14.02 software.

RESULTS

Expression of MMP-9 was noted in almost 83% of the tumours, expression of E-cadherin in 77% of tumours, while expression of Ki-67 antigen was detected in fewer than 26% of studied tumours.

CONCLUSION

The positive correlation (r=0.375) between expressions of MMP-9 and Ki-67 and negative correlations between E-cadherin and Ki-67 (r=-0.383) as well as between MMP-9 and E-cadherin (r=-0.45) could suggest that expression and biological significance of the studied markers in mammary adenocarcinomas in dogs resembles the pattern noted in ductal carcinoma, i.e. in the most frequent histological type of malignant tumour in humans. This may point to suitability of the animal model in studies on mechanism of neoplasia and metastases in humans.

Melatonin: adjuvant therapy of malignant tumors

This review summarizes the most relevant data relating to the potential role of melatonin (pineal secretory product) as an adjuvant therapy of tumors. Results of clinical studies were preceded by a description of experiments conducted on tumor cell lines and on laboratory animals. Most of the reports unequivocally confirmed the antioxidative and immunostimulatory action of the pineal secretory product in both in vitro and in vivo experiments. Results of studies on cell lines of various tumors showed that the anti-proliferative effect of melatonin might involve a receptor-mediated mechanism. In experiments on animals, the cardio-, nephro-, and myelo-protective action of melatonin was confirmed in the course of application of various cytostatic drugs. A meta-analysis of clinical studies in which melatonin was applied as an adjuvant drug in the therapy of various tumors pointed to some effects of its administration. Therefore, the use of melatonin could offer hope in future antitumor therapy.

Development of foreign body giant cells in response to implantation of Spongostan as a scaffold for cartilage tissue engineering

Spongostan, a gelatinous haemostatic sponge, is used in surgery. Moreover, Spongostan may serve as a scaffold for proteins or cells implanted into defects. At the site of biomaterial implantation, foreign body giant cells (FBGCs) may develop which are responsible for Spongostan degradation. The purpose of the present study was to examine whether Spongostan may serve as a scaffold in allogenic grafting of chondrocytes developed from rabbit auricular cartilage. The obtained results indicate that Spongostan fulfils its function as a cell scaffold, induces no inflammatory reaction and involves development of foreign body giant cells which participate in the process of its degradation. Microscopic observation showed that FBGCs manifest presence of cytoplasmic projections and lysosomes, which participate in phagocytosis of the applied scaffold.

Effect of melatonin on cytotoxicity of doxorubicin toward selected cell lines (human keratinocytes, lung cancer cell line A-549, laryngeal cancer cell line Hep-2)

The pineal hormone melatonin (MLT) has been recognised as a substance capable of alleviating in vivo nephro-, cardio- and myelotoxicity of doxorubicin (DOX) and of other anthracyclines in animal models. However, few data are available on the effects of MLT on cytotoxicity of antineoplastic drugs toward tumor cells in vitro. The present study aimed at the evaluation of effects of MLT and of DOX on selected cell lines. The experiments were conducted on human keratinocytes (primary culture), non-small cell lung cancer (A-549) and laryngeal cancer cell lines (HEp-2). In keratinocytes and in A-549 cells, MLT used at pharmacological concentrations (0.1 and 1.0 mM) was observed to intensify apoptotic lesions. MLT exerted no clear-cut effects on the HEp-2 cell line. In contrast, DOX at concentrations of 0.1 and 1.0 microg/ml intensified apoptosis and augmented the frequency of necrotic lesions in cell nuclei in all the examined cell lines. MLT intensified cytotoxicity of DOX in all cell lines, significantly decreasing cell numbers and promoting apoptosis. The effect was MLT concentration-dependent. MLT decreased the proportion of cells with necrotic lesions.

Prognostic significance of metallothionein, p53 protein and Ki-67 antigen expression in laryngeal cancer

BACKGROUND

This study aimed at the evaluation of the expression of metallothionein (MT) in laryngeal carcinoma and its correlation with the expression of Ki-67 antigen and p53 protein and selected clinical and pathological variables in view of their potential prognostic significance.

MATERIALS AND METHODS

Sixty-five laryngeal cancer patients were retrospectively analysed. Expression of MT, Ki-67 and p53 in tumour tissue samples were assessed by immunohistochemistry.

RESULTS

In laryngeal cancer a significantly augmented expression of MT, Ki-67 and p53 was noted, as compared to the control group (p < 0.001) and a significantly increased expression of MT in low malignancy tumours (G1) as compared to the control group (p < 0.001). The expression of Ki-67 antigen was positively correlated with the expression of p53 protein (r = 0.477; p < 0.05) and expression of either marker was positively correlated with malignancy grade (r = 0.47, p < 0.05; r = 0.31, p < 0.05; for Ki-67 and p53, respectively). Shortened survival was noted in patients with high expression of Ki-67 antigen and p53 protein.

CONCLUSION

The intensity of MT expression was not related to prognosis in laryngeal cancer. Nevertheless, it may provide a significant index indicating the malignant transformation of benign lesions of laryngeal epithelium.

Effects of adaptive exercise on apoptosis in cells of rat renal tubuli

Regular exercise is known to improve physiological and functional capacity of many organs due to adaptive processes. We have previously shown that acute exercise in untrained rats results in apoptosis of renal tubular cells and that the apoptotic process seems to be associated with stimulation of angiotensin II, AT1 and AT2 receptors. In this study, we examined the influence of regular training on apoptosis and the role of angiotensin II receptors and antioxidant enzymes in mediating the adaptive response in renal tubular cells. We measured apoptosis, expression of AT1 and AT2 receptors, level of lipid peroxidation (TBARS) and activities of antioxidant enzymes, SOD, GPx and CAT in kidneys of sedentary rats that were exposed to acute exercise and rats that were trained for 8 weeks. In untrained animals, the acute exercise resulted in increased apoptosis and increased expression of AT1 and AT2 receptors in renal tubular cells, while in the rats exposed to the 8-week regular training, there were no changes in apoptosis nor AT1 and AT2 receptor expression as compared to the sedentary animals. The TBARS levels were significantly increased in acutely exercised rats, while in rats pre-exposed to the training they remained unchanged. The acute exercise, as well as regular training, did not change SOD, CAT or GPx activities. These findings suggested that the acute exercise-induced apoptosis in renal tubules could involve action of AT1 and AT2 receptors as well as oxidative stress, while the regular training was shown to prevent apoptosis in renal tubular cells via modulated expression of AT1 and AT2 receptors.

Exercise-induced apoptosis in rat kidney is mediated by both angiotensin II AT1 and AT2 receptors

Excessive physical exercise may lead to disturbance of the entire homeostasis in the body, including damage not only in skeletal muscles but also in many distant organs. The mechanisms responsible for the exercise-induced changes could include oxidative stress or angiotensin II. We previously showed that acute exercise led to apoptosis in kidney but not as a result of oxidative stress. In this study, we examined the role of angiotensin II and its AT1 and AT2 receptors in mediation of exercise-induced apoptosis in kidney. We clearly demonstrated that acute physical exercise induced apoptosis in renal cells of distal convoluted tubuli and cortical and medullary collecting ducts. Moreover, the cells displayed an increased expression of both AT1 and AT2 angiotensin II receptors and of p53 protein. The results suggest that angiotensin II could upregulate p53 expression in renal distal convoluted tubular cells and in the cells collecting ducts via both AT1 and AT2 receptors, which might be the crucial apoptosis-mediating mechanism in kidneys after excessive exercise.

Long-term denervation in humans causes degeneration of both contractile and excitation-contraction coupling apparatus, which is reversible by functional electrical stimulation (FES): a role for myofiber regeneration?

Over the last 30 years there has been considerable interest in the use of functional electrical stimulation (FES) to restore movement to the limbs of paralyzed patients. Spinal cord injury causes a rapid loss in both muscle mass and contractile force. The atrophy is especially severe when the injury involves lower motoneurons because many months after spinal cord injury, atrophy is complicated by fibrosis and fat substitution. In this study we describe the effects of long-term lower motoneuron denervation of human muscle and present the structural results of muscle trained using FES. By means of an antibody for embryonic myosin, we demonstrate that many regenerative events continue to spontaneously occur in human long-term denervated and degenerated muscle (DDM). In addition, using electron microscopy, we describe i) the overall structure of fibers and myofibrils in long-term denervated and degenerated muscle, including the effects of FES, and ii) the structure and localization of calcium release units, or triads; the structures reputed to activate muscle contraction during excitation-contraction coupling (ECC). Both apparatus undergo disarrangement and re-organization following long-term denervation and FES, respectively. The poor excitability of human long-term DDM fibers, which extends to the first periods of FES training, may be explained in terms of the spatial disorder of the ECC apparatus. Its disorganization and re-organization following long-term denervation and FES, respectively, may play a key role in the parallel disarrangement and re-organization of the myofibrils that characterize denervation and FES training. The present structural studies demonstrate that the protocol used during FES training is effective in reverting long-term denervation atrophy and dystrophy. The mean fiber diameter in FES biopsies is 42.2 +/- 14.8 SD (p < 0.0001 vs DDM 14.9 +/- 6.0 SD); the mean percentile of myofiber area of the biopsy is 94.3 +/- 5.7 SD (p < 0.0001 vs DDM 25.7 +/- 23.7 SD); the mean percentile fat area is 2.1 +/- 2.4 SD (p < 0.001 vs DDM 12.8 +/- 12.1 SD); and the mean percentile connective tissue area is 3.6 +/- 4.6 SD (p < 0.001 vs DDM 61.6 +/- 20.1 SD). In DDM biopsies more than 50% of myofibers have diameter smaller than 10 microm, while the FES-trained subjects have more that 50% of myofibers larger than 30 microm. The recovery of muscle mass seems to be the result of both a size increase of the surviving fibers and the regeneration of new myofibers.

Long-term denervation in humans causes degeneration of both contractile and excitation-contraction coupling apparatus, which is reversible by functional electrical stimulation (FES): a role for myofiber regeneration?

Over the last 30 years there has been considerable interest in the use of functional electrical stimulation (FES) to restore movement to the limbs of paralyzed patients. Spinal cord injury causes a rapid loss in both muscle mass and contractile force. The atrophy is especially severe when the injury involves lower motoneurons because many months after spinal cord injury, atrophy is complicated by fibrosis and fat substitution. In this study we describe the effects of long-term lower motoneuron denervation of human muscle and present the structural results of muscle trained using FES. By means of an antibody for embryonic myosin, we demonstrate that many regenerative events continue to spontaneously occur in human long-term denervated and degenerated muscle (DDM). In addition, using electron microscopy, we describe i) the overall structure of fibers and myofibrils in long-term denervated and degenerated muscle, including the effects of FES, and ii) the structure and localization of calcium release units, or triads; the structures reputed to activate muscle contraction during excitation-contraction coupling (ECC). Both apparatus undergo disarrangement and re-organization following long-term denervation and FES, respectively. The poor excitability of human long-term DDM fibers, which extends to the first periods of FES training, may be explained in terms of the spatial disorder of the ECC apparatus. Its disorganization and re-organization following long-term denervation and FES, respectively, may play a key role in the parallel disarrangement and re-organization of the myofibrils that characterize denervation and FES training. The present structural studies demonstrate that the protocol used during FES training is effective in reverting long-term denervation atrophy and dystrophy. The mean fiber diameter in FES biopsies is 42.2 +/- 14.8 SD (p < 0.0001 vs DDM 14.9 +/- 6.0 SD); the mean percentile of myofiber area of the biopsy is 94.3 +/- 5.7 SD (p < 0.0001 vs DDM 25.7 +/- 23.7 SD); the mean percentile fat area is 2.1 +/- 2.4 SD (p < 0.001 vs DDM 12.8 +/- 12.1 SD); and the mean percentile connective tissue area is 3.6 +/- 4.6 SD (p < 0.001 vs DDM 61.6 +/- 20.1 SD). In DDM biopsies more than 50% of myofibers have diameter smaller than 10 microm, while the FES-trained subjects have more that 50% of myofibers larger than 30 microm. The recovery of muscle mass seems to be the result of both a size increase of the surviving fibers and the regeneration of new myofibers.

Functional in vivo gene transfer into the myofibers of adult skeletal muscle

The postmitotic nature and longevity of skeletal muscle fibers permit stable expression of any transfected gene. Direct in vivo injection of plasmid DNA, in both adult and regenerating muscles, is a safe, inexpensive, and easy approach. Here we present an optimized electroporation protocol based on the use of spatula electrodes to transfer cDNA in vivo into the adult myofibers of an anatomically defined muscle, which could be functionally characterized. In our hands, about 80% of adult myofibers were transfected in vivo by different plasmids for GFP fusion proteins or for beta-galactosidase. The luciferase activity increased several orders of magnitude when compared to standard DNA delivery. In an anatomical defined muscle, the wide gene transfer was comparable to or better than that of retrovirus delivery, that recently has been shown to be prone to severe side-effects in human clinical studies. Furthermore, with our method the tissue damage was greatly decreased. Thus, the present work describes in vivo functional electrotransfer of genes in adult skeletal muscle fibers by a protocol that is of great potential for gene therapy, as well as for basic research.

Influence of exogenous melatonin on doxorubicin-evoked effects in myocardium and in transplantable Morris hepatoma in rats

BACKGROUND

Melatonin is one of the most effective oxygen free radical scavengers. Its cardio- and nephro-protective effects were demonstrated in the course of anthracycline administration. The present study aimed at examining the cytostatic efficiency of doxorubicin (DOX) applied together with melatonin to rats with transplantable Morris hepatoma.

MATERIALS AND METHODS

Animals were divided into four groups receiving 0.9% NaCl, melatonin, DOX and melatonin together with DOX, respectively. Three weeks after transplantation of the tumour cells, the heart and tumour were isolated. The extent of tumour necrosis and the number of apoptotic cells were evaluated in paraffin-embedded sections.

RESULTS

Administration of melatonin together with DOX decreased the extent of tumour necrosis and the apoptotic tumour cells but, on the other hand, decreased the number of apoptotic cardiomyocytes.

CONCLUSION

Melatonin weakens the cytotoxic activity of DOX by the decreased proportions of necrotic and apoptotic cells of transplantable Morris hepatoma. Melatonin protects also cardiomyocytes by decreasing DOX-induced apoptosis in the cells.

Apoptosis of myofibres and satellite cells: exercise-induced damage in skeletal muscle of the mouse

Apoptosis is well accepted as a type of cell death occurring in the development of mammalian muscles, but the death of adult myofibres in neuromuscular disorders and exercise-induced muscle damage is usually explained in terms of muscle necrosis. The current view that apoptosis precedes necrosis in death of dystrophin-deficient muscle fibres of mdx mouse has been well substantiated. Moreover, apoptotic myonuclei have been reported to increase in mdx mice 2 days after spontaneous exercise. To investigate the contribution of apoptosis to exercise-induced damage of normal muscle fibre a time-course analysis has been performed in adult C57BL/6 mice. Groups of five mice were sacrificed immediately after the end of the exercise, and after a rest period of 6 or 96 h. The amount of apoptosis in leg muscles was assessed by electron microscopy, by the terminal deoxynucleotidyl transferase assay and by electrophoretic detection of fragmented DNA; the expression of Bcl-2, Bax, Fas, ICE, p53 and ubiquitin was examined by immunohistochemistry and Western blot. Absent in muscles of normal 'sedentary' mice, apoptotic myonuclei peak in muscles of normal mice after a night of spontaneous wheel-running (4% +/- 3.5, immediately and 2.5% +/- 1.8 after 6 h rest, P < 0.05 vs non-runner mice); they then decrease but are present 4 days later (0.8% +/- 1.5). Satellite cells are also involved in the apoptotic process. Myofibre content of Bcl-2 decreases whereas Bax, Fas, ICE and ubiquitin modify their pattern of expression in correlation with the changes in apoptotic myonuclei. Apoptosis of endothelial cells is present after the night of wheel-running and with a twofold increase 4 days later (1.5 +/- 2.3 and 4.8 +/- 4.4 P < 0.05, respectively). Satellite cells are also involved in the apoptotic process. Thus, spontaneous running in unaccustomed mice increases the number of apoptotic nuclei in adult muscle fibres and in endothelial cells. It remains to be established whether muscle apoptosis is restricted to the repair mechanisms, as often suggested in many pathologic processes, or it is also part of pathogenesis of muscle damage. Regardless of whether these results are extended to human dystrophies, the clinical implications in terms of secondary pathogenetic mechanisms and muscle training are obvious.