Heat shock protein 27 and p16 immunohistochemistry in cervical intraepithelial neoplasia and squamous cell carcinoma

Functional Diversity of Mammalian Small Heat Shock Proteins: A Review

The small heat shock proteins (sHSPs), whose molecular weight ranges from 12∼43 kDa, are members of the heat shock protein (HSP) family that are widely found in all organisms. As intracellular stress resistance molecules, sHSPs play an important role in maintaining the homeostasis of the intracellular environment under various stressful conditions. A total of 10 sHSPs have been identified in mammals, sharing conserved α-crystal domains combined with variable N-terminal and C-terminal regions. Unlike large-molecular-weight HSP, sHSPs prevent substrate protein aggregation through an ATP-independent mechanism. In addition to chaperone activity, sHSPs were also shown to suppress apoptosis, ferroptosis, and senescence, promote autophagy, regulate cytoskeletal dynamics, maintain membrane stability, control the direction of cellular differentiation, modulate angiogenesis, and spermatogenesis, as well as attenuate the inflammatory response and reduce oxidative damage. Phosphorylation is the most significant post-translational modification of sHSPs and is usually an indicator of their activation. Furthermore, abnormalities in sHSPs often lead to aggregation of substrate proteins and dysfunction of client proteins, resulting in disease. This paper reviews the various biological functions of sHSPs in mammals, emphasizing the roles of different sHSPs in specific cellular activities. In addition, we discuss the effect of phosphorylation on the function of sHSPs and the association between sHSPs and disease.

Revisiting the Old Data of Heat Shock Protein 27 Expression in Squamous Cell Carcinoma: Enigmatic HSP27, More Than Heat Shock

Initially discovered to be induced by heat shock, heat shock protein 27 (HSP27, also called HSPB1), a member of the small HSP family, can help cells better withstand or avoid heat shock damage. After years of studies, HSP27 was gradually found to be extensively engaged in various physiological or pathophysiological activities. Herein, revisiting the previously published data concerning HSP27, we conducted a critical review of the literature regarding its role in squamous cell carcinoma (SCC) from the perspective of clinicopathological and prognostic significance, excluding studies conducted on adenocarcinoma, which is very different from SCC, to understand the enigmatic role of HSP27 in the tumorigenesis of SCC, including normal mucosa, dysplasia, intraepithelial neoplasm, carcinoma in situ and invasive SCC.

p16 is superior to Stathmin-1 and HSP27 in identifying cervical dysplasia

Background

The aim of this study was to determine how Stathmin-1 and Heat Shock Protein 27 (HSP27) can be used as adjunctive biomarkers to differentiate high-grade dysplasia from benign/reactive lesions in cervical tissues. In addition, we aimed to see if any of these markers can differentiate endometrial from endocervical adenocarcinomas.

Methods

Fifty cases including benign cervical tissue, low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), adenocarcinoma in situ of the endocervix, invasive endocervical adenocarcinoma, and endometrial adenocarcinoma were selected. Stathmin-1 and HSP27 immunohistochemistry (IHC) were performed for each case and the results were compared to the previously available p16 IHC stains.

Results

p16 stained positively in 100% of HSIL, endocervical adenocarcinoma in situ, and invasive endocervical cases. Stathmin-1 stained positively in 43% of HSIL and 90% of endocervical adenocarcinoma in situ and all invasive endocervical cases. Stathmin-1 and p16 were negative in all benign cervical samples. Stathmin-1, HSP27, and p16 stained 100% of LSIL cases. HSP27 stained indiscriminately, including 100% of benign cervical tissue. 87% of the endometrial adenocarcinomas stained positively for p16, Stathmin-1, and HSP27.

Conclusion

p16 remains superior to both Stathmin-1 and HSP27 in differentiating dysplasia from benign, reactive changes of the cervix.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13000-021-01144-w.

Small Heat Shock Proteins in Cancers: Functions and Therapeutic Potential for Cancer Therapy

Small heat shock proteins (sHSPs) are ubiquitous ATP-independent chaperones that play essential roles in response to cellular stresses and protein homeostasis. Investigations of sHSPs reveal that sHSPs are ubiquitously expressed in numerous types of tumors, and their expression is closely associated with cancer progression. sHSPs have been suggested to control a diverse range of cancer functions, including tumorigenesis, cell growth, apoptosis, metastasis, and chemoresistance, as well as regulation of cancer stem cell properties. Recent advances in the field indicate that some sHSPs have been validated as a powerful target in cancer therapy. In this review, we present and highlight current understanding, recent progress, and future challenges of sHSPs in cancer development and therapy.

Ki-67 and P16 proteins in cervical cancer and precancerous lesions of young women and the diagnostic value for cervical cancer and precancerous lesions

Expression of Ki-67 and P16 proteins in cervical cancer and precancerous lesions of young women and the diagnostic value for cervical cancer and precancerous lesions were investigated. A total of 64 paraffin-embedded specimens of uterus tissue from young female patients who were admitted to Jiading District Central Hospital Affiliated to Shanghai University of Medicine and Health Sciences from January 2015 to December 2017 were selected. According to pathological examination, the specimens were divided into chronic cervicitis group (control group, 10 cases), low-grade squamous intraepithelial lesion (LSIL) group (12 cases), high-grade squamous intraepithelial lesion (HSIL) group (20 cases) and squamous carcinoma of the cervix (SCC) group (22 cases). Expression of Ki-67 and P16 protein was detected by immunohistochemistry and the diagnostic values were analyzed. Positive rates of Ki-67 and P16 expression in HSIL and SCC groups were significantly higher than those in LSIL and control groups (P<0.05), but there was no significant difference between LSIL and control groups (P>0.05). Spearman's analysis showed that the expression levels of Ki-67 and P16 were positively correlated with the degree of cervical lesions (rs=0.725; rs=0.829), and their expression levels were also positively correlated (rs=0.772). Sensitivity and specificity analysis showed that the Ki-67 diagnosis has higher sensitivity (95.2%), but the specificity is poor (86.7%). Diagnosis using P16 has high specificity (94.6%), but the sensitivity is poor (85.4%). When the two were combined for diagnosis, sensitivity (94.8%) and specificity (93.2%) were both at a high level. The combined detection of Ki-67 and P16 protein has a high application prospect as an auxiliary diagnosis of SCC.

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.

Diagnostic value of HMGB1 immunostaining on cell blocks from residual liquid-based gynecologic cytology specimens

Aberrant expression of high mobility group box 1 (HMGB1) is associated with tumor development and progression. The current study was conducted to evaluate the significance of HMGB1 immunostaining on cell block (CB) preparations in the diagnosis of neoplastic and preneoplastic lesions of the cervix. The CBs were prepared from 157 residual liquid-based gynecologic cytology specimens which were collected from women whose cervical lesions had been confirmed by histopathology. The expression of HMGB1 and p16INK4A (p16) was visualized by immunocytochemistry on the CB preparations, and the association of their expression patterns was correlated with the severity of cervical lesions. HeLa cells were used as positive control. HMGB1 expression was observed in dysplastic and neoplastic cells and increased along with the progression of cervical neoplasia. The rates of positive staining for HMGB1 in cervical intraepithelial neoplasia 1 (CIN-1), CIN-2, CIN-3, and invasive squamous cell carcinomas (ISCCs) were 69.4, 96.9, 100.0, and 100.0%, respectively. The differences between positive rates of patients with chronic cervicitis and various CINs as well as ISCCs were significant (P < 0.005). The differences in positive staining rates between each two CIN groups, and differences between CIN-1/2 and ISCCs, were also significant (P < 0.005). The expression pattern of HMGB1 was generally correlated with that of p16 (P < 0.001). HMGB1 staining was observed in some p16-negative specimens. HMGB1 immunostaining on a CB from gynecologic cytology specimens is potentially valuable for the screening of cervical lesions in cases with questionable cytology.

Heat shock proteins and heat shock factor 1 in carcinogenesis and tumor development: an update

Heat shock proteins (HSP) are a subset of the molecular chaperones, best known for their rapid and abundant induction by stress. HSP genes are activated at the transcriptional level by heat shock transcription factor 1 (HSF1). During the progression of many types of cancer, this heat shock transcriptional regulon becomes co-opted by mechanisms that are currently unclear, although evidently triggered in the emerging tumor cell. Concerted activation of HSF1 and the accumulation of HSPs then participate in many of the traits that permit the malignant phenotype. Thus, cancers of many histologies exhibit activated HSF1 and increased HSP levels that may help to deter tumor suppression and evade therapy in the clinic. We review here the extensive work that has been carried out and is still in progress aimed at (1) understanding the oncogenic mechanisms by which HSP genes are switched on, (2) determining the roles of HSF1/HSP in malignant transformation and (3) discovering approaches to therapy based on disrupting the influence of the HSF1-controlled transcriptome in cancer.