Sec62/Ki67 and p16/Ki67 dual-staining immunocytochemistry in vulvar cytology for the identification of vulvar intraepithelial neoplasia and vulvar cancer: a pilot study

Ki-67 as a Prognostic Marker in Squamous Cell Carcinomas of the Vulva: A Systematic Review

Background/Objectives: To evaluate the prognostic impact of immunohistochemical ki-67 staining analysis regarding lymph node involvement and survival data (overall/progression-free survival) in squamous cell carcinoma of the vulva. Methods: A systematic literature search of English and German articles was conducted (PubMed, Embase, Scopus, Web of Science) from 1980 to December 2023, including the search terms "vulvar Neoplasms", "vulvar cancer", "vulvar carcinoma", "vulvar tumor", "vulvar tumour", "vulvar malignancy", "vulvar malignant", "ki-67", "MIB-1", "MIB1", "proliferative index", "proliferative activity", "mitotic index", and "mitotic count". Study quality was assessed using a two-step "mixed-criteria" approach; to synthesize study results, a narrative summary is provided. Results: In total, 13 studies were included in this systematic literature review. In general, two distinct methods of staining interpretation could be retrieved: A "pattern-based" method, as well as a cell count-based method. Ten of the included studies examined the relationship between ki-67 and lymph node involvement, nine studies included survival data as a parameter of interest; and only five studies defined both groin lymph node metastasis and survival data as outcome variables. While nine out of ten studies found no statistically significant association between ki-67 staining and lymph node metastasis, five out of nine studies determined an association between ki-67 status and overall survival, especially when employing a "pattern-based" method of staining interpretation. Conclusions: The prognostic value of ki-67 staining in terms of survival data has been reported ambivalently and should be subject to future studies. Furthermore, we did not find convincing evidence of an association between ki-67 and lymph node involvement.

Dual Sec62/Ki67 immunocytochemistry of liquid-based cytological preparations represents a highly valid biomarker for non-invasive detection of head and neck squamous cell carcinomas

BACKGROUND

Head and neck squamous cell carcinomas (HNSCC) are frequently diagnosed in advanced stages, which limits therapeutic options and results in persistently poor patient outcomes. The aim of this study was to use liquid-based swab cytology (LBC) in combination with dual immunocytochemical detection of migration and proliferation markers Sec62 and Ki67 in order to allow non-invasive early detection of HNSCC as well as to analyse the diagnostic validity of this method for predicting the malignancy of suspicious oral lesions.

METHODS

104 HNSCC patients and 28 control patients, including healthy patients (n = 17), papilloma (n = 1) and leukoplakia patients (n = 10), were included in this study. For all patients, an LBC swab followed by simultaneous immunocytochemical detection of Sec62 and Ki67 was performed. Immunocytochemical as well as cytopathological results were correlated with histological diagnoses and clinical findings.

RESULTS

All HNSCC patients (100%) showed dual Sec62/Ki67 positivity, and all control patients except for the papilloma patient were negative for Sec62/Ki67 (96.4%), resulting in a 100% sensitivity and 96.4% specificity of Sec62/Ki67 dual stain for non-invasive detection of HNSCC. The positive predictive value was 99% and the negative predictive value was 100%. Sec62 expression levels showed a positive correlation with tumour de-differentiation (p = 0.0489).

CONCLUSION

Simultaneous immunocytochemical detection of Sec62/Ki67 using LBC represents a promising non-invasive and easy-to-apply tool for the early detection of HNSCC in routine clinical practice. This novel technique can help to avoid incisional biopsies and reduce the frequency with which general anaesthesia is used in diagnostic procedures in patients with suspicious oral lesions.

An integrated model for prognosis in vulvar squamous cell carcinoma

BACKGROUND

Vulvar squamous cell carcinoma (VSCC) is a relatively rare gynecologic cancer. Unlike cervical squamous cell carcinoma (CSCC), in which nearly all cases are caused by HPV infection, most VSCCs are HPV-independent. Patients with VSCC also have worse overall survival (OS) than those with CSCC. Unlike CSCC, the risk factors of VSCC have not been extensively studied. Here, we investigated the prognostic values of clinicopathological parameters as well as biomarkers in patients with VSCC.

METHODS

In total, 69 cases of VSCC accessions were selected for analysis between April 2010 and October 2020. The risk factors of VSCC were screened using Cox models to establish nomograms for predicting survival outcomes.

RESULTS

Following the multivariate COX model for OS, independent predictors including advanced age (hazard ratio [HR] 5.899, p = 0.009), HPV positivity (HR 0.092, p = 0.016), high Ki-67 index (HR 7.899, p = 0.006), PD-L1-positivity (HR 4.736, p = 0.077), and CD8 + tumor-infiltrating lymphocytes (TILs) (HR 0.214, p = 0.024) were included in the nomogram for OS; multivariate COX model for progression-free survival (PFS) was used to screen prognostic factors including advanced age (HR 2.902, p = 0.058), lymph node metastasis (HR 5.038, p = 0.056), HPV positivity (HR 0.116, p = 0.011), high Ki-67 index (HR 3.680, p = 0.042), PD-L1-positivity (HR 5.311, p = 0.045), and CD8 + TILs (HR 0.236, p = 0.014) to establish the PFS nomogram model. Based on the C-index (0.754 for OS and 0.754 for PFS) from our VSCC cohort and the corrected C-index (0.699 for OS and 0.683 for PFS) from an internal validation cohort, the nomograms demonstrated good predictive and discriminative ability. Kaplan-Meier curves also supported the excellent performance of the nomograms.

CONCLUSION

Our prognostic nomograms suggested that (1) shorter OS and PFS were associated with PD-L1-positivity, high Ki-67 index, and low CD8 + TILs; (2) HPV-independent tumors were associated with poorer survival outcome, and mutant p53 status showed no prognostic significance.

Co-chaperones of the Human Endoplasmic Reticulum: An Update

In mammalian cells, the rough endoplasmic reticulum (ER) plays central roles in the biogenesis of extracellular plus organellar proteins and in various signal transduction pathways. For these reasons, the ER comprises molecular chaperones, which are involved in import, folding, assembly, export, plus degradation of polypeptides, and signal transduction components, such as calcium channels, calcium pumps, and UPR transducers plus adenine nucleotide carriers/exchangers in the ER membrane. The calcium- and ATP-dependent ER lumenal Hsp70, termed immunoglobulin heavy-chain-binding protein or BiP, is the central player in all these activities and involves up to nine different Hsp40-type co-chaperones, i.e., ER membrane integrated as well as ER lumenal J-domain proteins, termed ERj or ERdj proteins, two nucleotide exchange factors or NEFs (Grp170 and Sil1), and NEF-antagonists, such as MANF. Here we summarize the current knowledge on the ER-resident BiP/ERj chaperone network and focus on the interaction of BiP with the polypeptide-conducting and calcium-permeable Sec61 channel of the ER membrane as an example for BiP action and how its functional cycle is linked to ER protein import and various calcium-dependent signal transduction pathways.

The endoplasmic reticulum membrane protein Sec62 as potential therapeutic target in SEC62 overexpressing tumors

The human SEC62 gene is located on chromosome 3q, was characterized as a tumor driver gene and is found to be overexpressed in an ever-growing number of tumors, particularly those with 3q26 amplification. Where analyzed, SEC62 overexpression was associated with poor prognosis. Sec62 protein is a membrane protein of the endoplasmic reticulum (ER) and has functions in endoplasmic reticulum protein import, endoplasmic reticulum-phagy and -in cooperation with the cytosolic protein calmodulin- the maintenance of cellular calcium homeostasis. Various human tumors show SEC62 overexpression in immunohistochemistry and corresponding cell lines confirm this phenomenon in western blots and immunofluorescence. Furthermore, these tumor cells are characterized by increased stress tolerance and migratory as well as invasive potential, three hallmarks of cancer cells. Strikingly, plasmid-driven overexpression of SEC62 in non-SEC62 overexpressing cells introduces the same three hallmarks of cancer into the transfected cells. Depletion of Sec62 from either type of SEC62 overexpressing tumor cells by treatment with SEC62-targeting siRNAs leads to reduced stress tolerance and reduced migratory as well as invasive potential. Where tested, treatment of SEC62 overexpressing tumor cells with the small molecule/calmodulin antagonist trifluoperazine (TFP) phenocopied the effect of SEC62-targeting siRNAs. Recently, first phase II clinical trials with the prodrug mipsagargin/G202, which targets cellular calcium homeostasis in prostate cells as well as neovascular tissue in various tumors were started. According to experiments with tumor cell lines, however, SEC62 overexpressing tumor cells may be less responsive or resistant against such treatment. Therefore, murine tumor models for tumor growth or metastasis were evaluated with respect to their responsiveness to treatment with a mipsagargin analog (thapsigargin), or trifluoperazine, which had previously been in clinical use for the treatment of schizophrenia, or with the combination of both drugs. So far, no additive effect of the two drugs was observed but trifluoperazine had an inhibitory effect on tumor growth and metastatic potential in the models. Here, we review the state of affairs.

Role of the SEC62 gene in dermato-oncology - impact on tumor cell biology, prognostication, and personalized therapy management

The SEC62 gene encodes for a transmembrane protein of the endoplasmic reticulum (ER). Sec62 protein is involved in the post-translational transport of secretory and membrane-bound proteins in eukaryotic cells, regulates intracellular calcium homeostasis through direct interaction with the Sec61 channel and makes a decisive contribution to the cellular compensation of ER stress in the context of recovER-phagy. A significantly increased expression of the SEC62 gene has already been demonstrated in various tumor entities. First approaches of a targeted therapy have been tested for various tumor entities in vitro and in vivo with promising results that motivate further preclinical and clinical studies. Nevertheless, many questions remain unanswered, in particular with regard to the molecular mechanisms underlying the observed clinical effects, and require further investigation in future studies. The protein also plays a relevant role in dermato-oncology. The overexpression of SEC62 in atypical fibroxanthomas and malignant melanomas has already been demonstrated and a correlation of SEC62 expression with various clinical and pathological features has been observed. Future studies, especially in vivo and clinical, will show whether Sec62 can be established as a prognostic marker in dermato-oncology and whether it can serve as a starting point for targeted therapy.

Preliminary Study on the Expression of Testin, p16 and Ki-67 in the Cervical Intraepithelial Neoplasia

Cervical cancer is one of the most common malignant cancers in women worldwide. The 5-year survival rate is 65%; nevertheless, it depends on race, age, and clinical stage. In the oncogenesis of cervical cancer, persistent HPV infection plays a pivotal role. It disrupts the expression of key proteins as Ki-67, p16, involved in regulating the cell cycle. This study aimed to identify the potential role of testin in the diagnosis of cervical precancerous lesions (CIN). The study was performed on selected archival paraffin-embedded specimens of CIN1 (31), CIN2 (75), and CIN3 (123). Moderate positive correlation was observed between testin and Ki-67 as well as testin and p16 expression in all dysplastic lesions (r = 0.4209, r = 0.5681; p < 0.0001 for both). Statistical analysis showed stronger expression of the testin in dysplastic lesions vs. control group (p < 0.0001); moreover, expression was significantly higher in HSIL than LSIL group (p < 0.0024). In addition, a significantly stronger expression of testin was observed in CIN3 vs. CIN1 and CIN3 vs. CIN2. In our study, expression of Ki-67, p16, and testin increased gradually as the lesion progressed from LSIL to HSIL. The three markers complemented each other effectively, which may improve test sensitivity and specificity when used jointly.

Complexity and Specificity of Sec61-Channelopathies: Human Diseases Affecting Gating of the Sec61 Complex

The rough endoplasmic reticulum (ER) of nucleated human cells has crucial functions in protein biogenesis, calcium (Ca2+) homeostasis, and signal transduction. Among the roughly one hundred components, which are involved in protein import and protein folding or assembly, two components stand out: The Sec61 complex and BiP. The Sec61 complex in the ER membrane represents the major entry point for precursor polypeptides into the membrane or lumen of the ER and provides a conduit for Ca2+ ions from the ER lumen to the cytosol. The second component, the Hsp70-type molecular chaperone immunoglobulin heavy chain binding protein, short BiP, plays central roles in protein folding and assembly (hence its name), protein import, cellular Ca2+ homeostasis, and various intracellular signal transduction pathways. For the purpose of this review, we focus on these two components, their relevant allosteric effectors and on the question of how their respective functional cycles are linked in order to reconcile the apparently contradictory features of the ER membrane, selective permeability for precursor polypeptides, and impermeability for Ca2+. The key issues are that the Sec61 complex exists in two conformations: An open and a closed state that are in a dynamic equilibrium with each other, and that BiP contributes to its gating in both directions in cooperation with different co-chaperones. While the open Sec61 complex forms an aqueous polypeptide-conducting- and transiently Ca2+-permeable channel, the closed complex is impermeable even to Ca2+. Therefore, we discuss the human hereditary and tumor diseases that are linked to Sec61 channel gating, termed Sec61-channelopathies, as disturbances of selective polypeptide-impermeability and/or aberrant Ca2+-permeability.