Heat shock proteins expression in canine intracutaneous cornifying epithelioma and squamous cell carcinoma

Canine heat shock protein 27 promotes proliferation, migration, and doxorubicin resistance in the canine cell line DTK-F

Canine mammary tumors (CMTs) are the most common type of tumors in female dogs. Heat shock proteins are highly expressed in many cancers and are involved in tumor progression and chemoresistance in CMTs; however, the biological role of canine heat shock protein 27 (cHSP27) in CMTs has not been thoroughly characterized. This study investigated the roles of cHSP27 in cell growth, migration, anchorage, and resistance to doxorubicin (DOX) using DTK-F cells, a CMT cell line that does not express cHSP27. DTK-F cells were transfected with cHSP27 and stable overexpression was established. A mouse monoclonal antibody against cHSP27 was also produced. The biological functions of cHSP27 in DTK-F cells were then evaluated using a variety of assays. Overexpression of cHSP27 was associated with increased cell proliferation, clone formation, migration, and decreased DOX sensitivity. In conclusion, these data provide evidence that cHSP27 overexpression can promote anchorage-independent growth, migration, and increased DOX resistance in CMT cells.

HSP27 is commonly expressed in cervical intraepithelial lesions of Brazilian women

Heat shock proteins are molecular chaperones that may be constitutively present in cells protecting them from various stresses, such as extreme temperature, anoxia or chemical agents. Cervical cancer is the second most prevalent malignancy of women. In this study, we analyzed the expression of Hsp27 by immunohistochemistry in cervical intraepithelial lesions of Brazilian women, along with samples from non neoplasic lesions (NN). Cervical intraepithelial neoplasia I (CIN I), II (CIN II) and III (CIN III)/in situ carcinoma and squamous cell carcinoma (SCC) were included. Immunostaining was observed in 30 (100%) samples of NN, 46 (92%) in CIN I, 50 (100%) in CIN II, 52 (98.11%) in CIN III/CIS, and 46 (98.11%) in SCC. In group NN Hsp27 immunostaining was heterogeneous, more intense in basal and parabasal layers of the epithelium and less or absent in the intermediate and superficial layer. The majority of the samples of CIS and SCC presented strong staining in allepithelial layers. Metaplasic cells, when present, were strongly stained. In this study, Hsp27 protein was found to be commonly expressed in cervical epithelial cells.

Clinico-histopathologic and outcome features of cutaneous infundibular keratinizing acanthoma: a case report and literature review

The infundibular keratinizing acanthoma (IKA) is a rare epithelial benign keratin-containing neoplasm of hair follicles. The purpose of this study was to evaluate the defining histopathologic architecture of IKA. A typical IKA consisted of a keratin-filled crypt in the dermis and subcutis that opened to the skin surface. Most of this tumor occurred on the back, neck, head, and the shoulders. Microscopically, the dermal nodules were focally contiguous in both the dermis and subcutis. Furthermore, most histological lesions are consistent with a simple or multiloculated cyst filled with keratin and lined by a wall of stratified squamous epithelium; keratin appears as a concentric lamellar mass, with a keratotic pearly aspect. Histological examination of the cutaneous lesions revealed that the growths were comprised of IKA. IKA of man and dog were compared, and it was concluded that although they are similar in many respects, they are not identical entities. To the best of our knowledge, this is the first report on the prevalence of IKAs among the population of owned dogs in Iran.

Heat shock protein expression analysis in canine osteosarcoma reveals HSP60 as a potentially relevant therapeutic target

Heat shock proteins (HSP) are highly conserved across eukaryotic and prokaryotic species. These proteins play a role in response to cellular stressors, protecting cells from damage and facilitating recovery. In tumor cells, HSPs can have cytoprotective effects and interfere with apoptotic cascades. This study was performed to assess the prognostic and predictive values of the gene expression of HSP family members in canine osteosarcoma (OS) and their potential for targeted therapy. Gene expressions for HSP were assessed using quantitative PCR (qPCR) on 58 snap-frozen primary canine OS tumors and related to clinic-pathological parameters. A significant increased expression of HSP60 was found in relation to shorter overall survival and an osteoblastic phenotype. Therefore, the function of HSP60 was investigated in more detail. Immunohistochemical analysis revealed heterogeneous staining for HSP60 in tumors. The highest immunoreactivity was found in tumors of short surviving dogs. Next HSP expression was shown in a variety of canine and human OS cell lines by qPCR and Western blot. In two highly metastatic cell lines HSP60 expression was silenced using siRNA resulting in decreased cell proliferation and induction of apoptosis in both cell lines. It is concluded that overexpression of HSP60 is associated with a poor prognosis of OS and should be evaluated as a new target for therapy.

Epithelial-to-mesenchymal transition: immunohistochemical investigation of related molecules in canine cutaneous epithelial tumours

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) is a multistep process, important in tumour invasion and metastasis, characterized by loss of epithelial markers, redistribution of β-catenin and gain of mesenchymal markers. HYPOSTHESIS/OBJECTIVES: Our aim was to investigate the immunohistochemical aberrant expression of cytokeratin, vimentin, survivin and heat shock protein 72 (Hsp72) in canine cutaneous epithelial tumours, to understand the association of expression of these molecules with features of malignancy and their role in the EMT phenotype.

METHODS

Ten canine squamous cell carcinomas (SCCs; one with lymph node metastasis), 30 canine hair follicle tumours (six pilomatricomas, eight infundibular keratinizing acanthomas, six trichoepitheliomas and 10 trichoblastomas) and five normal skin samples were investigated by immunohistochemistry using specific anti-vimentin, -cytokeratin, -survivin and -Hsp72 antibodies. A semi-quantitative method was used to analyse the results, as follows: 0 to <5%; ≥ 5 to <10%; ≥ 10 to <25%; and ≥ 25% of positive cells. Immunofluorescence was performed to investigate survivin-vimentin and survivin-Hsp72 colocalization in selected SCCs. Results - In malignant hair follicle tumours and SCCs, a reduced intensity of cytokeratin and increased survivin and Hsp72 expression were observed. In SCCs, loss of cytokeratin expression and vimentin immunolabelling, suggestive of the EMT phenotype, were evident in <5% of neoplastic cells in the front of tumour invasion. In the same areas, strong nuclear survivin and cytoplasmic Hsp72 staining was evident, often colocalizing. Only a few neoplastic cells in the front of tumour invasion showed vimentin-survivin colocalization.

CONCLUSIONS AND CLINICAL IMPORTANCE

A possible simultaneous involvement of survivin and Hsp72 in tumour invasion and the multistep process of EMT of cutaneous epithelial tumours of dogs is suggested.

HSP27 and HSP70 expression in squamous cell carcinoma: An immunohistochemical study

BACKGROUND

Heat shock proteins (HSPs) are a family of proteins that are known to play a significant role in the repair of denatured proteins in the cell. It seems that cytoprotective properties of HSPs may help in malignant progression by facilitating tumor cell growth and survival. The purpose of this study is to evaluate HSP27 and HSP70 expression in various histopathological grades of squamous cell carcinoma (SCC).

MATERIALS AND METHODS

In this retrospective-analytical study, the sections of 51 formalin-fixed paraffin-embedded biopsy specimens of SCC from various sites of oral and paraoral regions and 10 normal oral mucosa were immunostained by Novolink Polymer technique to determine the expression of HSP27 and HSP70. Then the data were analyzed according to the Kruskal-Walis, Mann-Whitney and the Spearman correlation tests (P<0.05).

RESULTS

The expression of HSP27 in well-differentiated SCC was significantly higher than normal epithelium (P=0.007) and in moderately differentiated SCC higher than poorly-differentiated SCC (P=0.023). Inverse correlation was observed between HSP27 expression and SCC's histopathological grade (P=0.001, r=-0.448). There was no significant difference between HSP70 staining of specimens (P=0.38).

CONCLUSIONS

The present study revealed that the expression level of HSP27 was inversely related to histopathological grade of SCC and it may provide prognostic value for patients with SCC, but there was no significant relationship between the expression of HSP70 and histopathological grades of SCC.

Heat shock protein expression in canine osteosarcoma

Abnormal levels of heat shock proteins have been observed in a number of human neoplasms and demonstrate prognostic, predictive and therapeutic implications. Since osteosarcoma (OSA) in dogs provides an important model for the same disease in humans, the aim of this study was to evaluate the immunohistochemical expression of Hsp27, Hsp72, Hsp73 and Hsp90 in 18 samples of canine appendicular OSA, in relation to histological grade and overall survival (OS), in order to investigate their potential prognostic, predictive and/or therapeutic value. A semiquantitative method was used for the analysis of the results. Hsp27, Hsp73 and Hsp90 showed a variably intense, cytoplasmic and nuclear immunoreactivity that was not associated with histological type or grade. On the other hand, a high percentage of Hsp72 immunostaining was significantly associated with grade III (P < 0.01) and a lack of immunolabelling was significantly correlated to a longer OS (P = 0.006). Neoplastic emboli were occasionally positive for Hsp27, faintly immunoreactive for Hsp72 and intensely immunolabelled by Hsp73 and Hsp90. In conclusion, absence of Hsp72 immunosignal appears to be associated with a favourable prognosis whilst the widespread Hsp90 immunoreactivity detected in all tumour cases as well as in neoplastic emboli, suggests this protein could be targeted in the therapy of canine OSA, and likewise in its human counterpart.

Canine gastric carcinoma: immunohistochemical expression of cell cycle proteins (p53, p21, and p16) and heat shock proteins (Hsp27 and Hsp70)

Immunohistochemical staining for cell cycle proteins and heat shock proteins was performed on 17 canine gastric carcinomas. The immunoexpression of p53, p21, p16, Hsp27, and Hsp70 was investigated. A study was conducted to determine the histological type and parameters related to tumor malignancy. Possible associations and trends were assessed between the immunoexpression of each protein and tumor type as well as specific parameters of malignancy. High intratumor frequency of cellular p53 immunostaining was observed (61.96% average), but lower frequencies of p21 and p16 expression were present (34.65% and 10.41%, respectively). The p53 overexpression was associated with tumor infiltration (P = .0258). Expression of p21 was lower in undifferentiated carcinomas, and the loss of expression was associated with histopathological parameters characteristic of a poor prognosis such as lymphatic vessel invasion (P = .0258). The lack of p16 immunoreactivity was related to histopathological characteristics of malignancy such as the presence of evident and multiple nucleoli (P = .0475). In contrast, deep tumor infiltration was observed in those carcinomas with a high p16 index (P = .0475). Hsp70 appeared to be overexpressed in all gastric neoplasms included in this study. This is in contrast to Hsp27, because a group of tumors showed complete lack of Hsp27 immunoexpression, whereas the others displayed extensive Hsp27 immunostaining. The differences in Hsp27 did not correlate with any of the histopathological parameters, but Hsp27 immunoexpression was higher in the undifferentiated carcinoma. No significant differences in the expression of the proteins were found in canine gastric carcinomas according to their histological type. These findings may be useful for establishing a prognosis for canine gastric carcinoma.

Heat shock proteins in animal neoplasms and human tumours--a comparison

Heat shock proteins (HSPs) are implicated in all phases of cancer from proliferation, impaired apoptosis and sustained angiogenesis to invasion and metastasis. The presence of abnormal HSP levels in several human tumours suggests that these proteins could be used as diagnostic and/or prognostic markers, whilst the direct correlation between HSP expression and drug resistance in neoplastic tissues means they could also be used to predict cancer response to specific treatment. HSPs have also been successfully targeted in clinical trials modifying their expression or chaperone activity. Preliminary studies in veterinary medicine have also demonstrated the presence of altered HSP expression in neoplasms, and the study of carcinogenesis and the role of HSPs in animal models will surely be an additional source of information for clinical cancer research.

Apoptosis and anti-apoptotic heat shock proteins in canine cutaneous infundibular keratinizing acanthomas and squamous cell carcinomas

Cell stress and death are linked in the neoplastic process, and heat shock proteins appear to play an important role by inhibiting apoptotic pathways. The apoptotic rates in 9 canine infundibular keratinizing acanthomas (IKAs) and 17 canine squamous cell carcinomas (SCCs) were correlated with the immunohistochemical expression of caspase-3 and the antiapoptotic heat shock proteins Hsp27, 72 and 73. Apoptosis was evaluated using the terminal deoxynucleotidyl transferase biotin-dUTP nick end labelling (TUNEL) method. The absence of a correlation between the TUNEL index and active-caspase-3 expression, a paucity of active-caspase-3-positive cells and Hsp72 over-expression were considered to be indicative of inhibition of apoptosis, and suggestive that inhibition of cell death plays a key role in oncogenesis and tumour growth of some canine skin neoplasms.

Heat shock protein expression in canine malignant mammary tumours

Background

Abnormal levels of Heat Shock Proteins (HSPs) have been observed in many human neoplasms including breast cancer and it has been demonstrated that they have both prognostic and therapeutic implications. In this study, we evaluated immunohistochemical expression of HSPs in normal and neoplastic canine mammary glands and confronted these results with overall survival (OS), in order to understand the role of HSPs in carcinogenesis and to establish their potential prognostic and/or therapeutic value.

Methods

Immunohistochemical expression of Hsp27, Hsp72, Hsp73 and Hsp90 was evaluated in 3 normal canine mammary glands and 30 malignant mammary tumours (10 in situ carcinomas, 10 invasive carcinomas limited to local structures without identifiable invasion of blood or lymphatic vessels, 10 carcinomas with invasion of blood or lymphatic vessels and/or metastases to regional lymph nodes). A semi-quantitative method was used for the analysis of the results.

Results

Widespread constitutive expression of Hsp73 and Hsp90 was detected in normal tissue, Hsp72 appeared to be focally distributed and Hsp27 showed a negative to rare weak immunostaining. In mammary tumours, a significant increase in Hsp27 (P < 0.01), Hsp72 (P < 0.05) and Hsp90 (P < 0.01) expression was observed as well as a significant reduction in Hsp73 (P < 0.01) immunoreactivity compared to normal mammary gland tissue. Hsp27 demonstrated a strong positivity in infiltrating tumour cells and metaplastic squamous elements of invasive groups. High Hsp27 expression also appeared to be significantly correlated to a shorter OS (P = 0.00087). Intense immunolabelling of Hsp72 and Hsp73 was frequently detected in infiltrative or inflammatory tumour areas. Hsp90 expression was high in all tumours and, like Hsp73, it also showed an intense positivity in lymphatic emboli.

Conclusion

These results suggest that Hsp27, Hsp72 and Hsp90 are involved in canine mammary gland carcinogenesis. In addition, Hsp27 appears to be implicated in tumour invasiveness and its high immunodetection in invasive tumours is indicative of a poorer clinical outcome.