V. E. Popova

Objective: to study the expression of alpha-6/beta-4 integrin and laminin-332 in lymph node-positive luminal a breast cancer. Material and Methods. Surgical specimens from 110 patients with luminal a breast cancer (T1–2N0–3M0), who were treated at Tomsk Cancer Research Institute from 2016 to 2022, were analyzed. All patients were divided into two groups: those without lymph node metastases (n=81) and those with lymph node metastases (n=29). The immunohistochemical study was performed according to a standard procedure using antibodies to integrin alpha-6 subunit (ITGA6), integrin beta-4 subunit (ITGB4) and gamma-2 subunit of laminin-332 (LAMG2). Histological samples were digitized using whole-slide scanners. The scanned slices were analyzed using SlideViver V2.8 and QuantCenter software tools. Results. The positive expression of ITGB4 (66 % and 19 %; χ2=22.088; pConclusion. The expression of alpha-6/beta-4 integrin and laminin-332 correlates with lymph node metastasis, and the expression of gamma-2 subunit of lamnin-332 can serve as a marker for lymph node metastasis.

Laminins are a family of high-molecular-weight heterotrimeric glycoproteins of the extracellular matrix that play a key structural role in basement membranes. Although mutations in intracellular proteins remain the primary drivers of carcinogenesis, the role of changes in the expression and spatial distribution of laminins in the development of malignant neoplasms is gaining increasing importance. Primary focus is given to the patterns of laminin alterations in carcinomas of various localizations, as well as their role in the acquisition of invasive and metastatic potential by tumor cells. Furthermore, the prognostic significance of different laminin isoforms is discussed.

Aim. To study the features of the expression of the integrin subunit β4 in primary tumor tissue depending on the clinical and morphological parameters of breast cancer. Materials and methods. We examined biopsy samples from 49 patients with T1–4N0–3M0 breast cancer; the median age was 51.0 [44.0; 60.0] years. Patients did not receive neoadjuvant therapy. Surgical intervention involved resection of the mammary gland with axillary lymph node dissection or radical mastectomy. The expression of markers of estrogen receptor, progesterone receptor, c-erB-2 (Her2/neu), Ki67, CD104 (integrin subunit β4) was assessed using immunohistochemistry. Statistical processing of the results was carried out using the Statisctica 10.0 software package. Results. In the group of patients with N3 degree, cases with positive cytoplasmic/membrane colocalization of integrin subunit β4 expression were more frequently detected (45%), compared with observations where no such expression was found (8%; p = 0.002). Conclusion. Positive cytoplasmic/membrane colocalization of integrin subunit β4 expression is associated with the prevalence of lymphatic metastasis, which corresponds to N3 degree.