Cell Therapy with Human Reprogrammed CD8+ T-Cells Has Antimetastatic Effects on Lewis Lung Carcinoma in C57BL/6 Mice.

Using a model of Lewis lung carcinoma (LLC) in vitro and in vivo, we previously demonstrated increased antitumor activity in CD8+ T-cells reprogrammed with an MEK inhibitor and PD-1 blocker. In this follow-up study, we carried out the reprogramming of human CD8+ T-cells (hrT-cell) using the MEK inhibitor and PD-1 blocker and targeted LLC cells. The effects of hrT-cell therapy were studied in a mouse model of spontaneous metastasis of a solid LLC tumor. We found antimetastatic activity of hrT-cells, a decrease in the number of cancer cells and cancer stem cells in the lungs, and an increase in the number of T-cells in the blood (including effector T-cells). Thus, reprogramming of human CD8+ T-cells with an MEK inhibitor and PD-1 blocker with targeted training by tumor target cells is a potential platform for developing a new approach to targeted lung cancer therapy.

Analysis of Circulating Tumor and Cancer Stem Cells Provides New Opportunities in Diagnosis and Treatment of Small Cell Lung Cancer.

Current methods for diagnosis and treatment of small cell lung cancer (SCLC) have only a modest efficacy. In this pilot study, we analyzed circulating tumor cells (CTCs) and cancer stem cells (CSCs) in patients with SCLC to search for new diagnostic and prognostic markers and novel approaches to improve the treatment of the disease. In other forms of lung cancer, we showed a heterogeneity of blood CTCs and CSCs populations, as well as changes in other cell populations (ALDH+, CD87+CD276+, and EGF+Axl+) in smokers. A number of CTCs and CSCs in patients with SCLC have been shown to be resistant to chemotherapy (CT). High cytotoxic activity and resistance to apoptosis of reprogrammed CD3+CD8+ T-lymphocytes (rTcells) in relation to naive CD3+CD8+ T-lymphocytes was demonstrated in a smoking patient with SCLC (Patient G) in vitro. The target for rTcells was patient G's blood CSCs. Reprogramming of CD3+CD8+ T-lymphocytes was carried out with the MEK1/2 inhibitor and PD-1/PD-L1 pathway blocker nivolumab. The training procedure was performed with a suspension of dead CTCs and CSCs obtained from patient's G blood. The presented data show a new avenue for personalized SCLC diagnosis and targeted improvement of chemotherapy based on the use of both CTCs and CSCs.

Reprogrammed CD8+ T-Lymphocytes Isolated from Bone Marrow Have Anticancer Potential in Lung Cancer.

CD8+ T-lymphocytes play a key role in antitumor immune response. Patients with lung cancer often suffer from T-lymphocyte dysfunction and low T-cell counts. The exhaustion of effector T-lymphocytes largely limits the effectiveness of therapy. In this study, reprogrammed T-lymphocytes used MEK inhibitors and PD-1 blockers to increase their antitumor activity. Antitumor effects of reprogrammed T-lymphocytes were shown in vitro and in vivo in the Lewis lung carcinoma model. The population of T- lymphocytes with persistent expression of CCR7 was formed as a result of reprogramming. Reprogrammed T-lymphocytes were resistant to apoptosis and characterized by high cytotoxicity against Lewis lung carcinoma (LLC) cells in vitro. Administration of reprogrammed T-lymphocytes to C57BL/6 mice with LLC reduced the number of lung metastases. The antitumor effect resulted from the elimination of tumor cells and cancer stem cells, and the effect of therapy on cytotoxic T-lymphocyte counts. Thus, reprogramming of T-lymphocytes using MEK inhibitors is a promising approach for targeted therapy of lung cancer.

Cancer Stem Cells and Somatic Stem Cells as Potential New Drug Targets, Prognosis Markers, and Therapy Efficacy Predictors in Breast Cancer Treatment.

New drug targets, markers of disease prognosis, and more efficient treatment options are an unmet clinical need in breast cancer (BC). We have conducted a pilot study including patients with luminal B stage breast cancer IIA-IIIB. The presence and frequency of various populations of cancer stem cells (CSC) and somatic stem cells were assessed in the blood, breast tumor tissue, and normal breast tissue. Our results suggest that patients with BC can be divided into two distinct groups based on the frequency of aldehyde dehydrogenase positive cells (ALDH1+ cells) in the blood (ALDH1hi and ALDH1low). In the ALDH1hi cells group, the tumor is dominated by epithelial tumor cells CD44+CD24low, CD326+CD44+CD24-, and CD326-CD49f+, while in the ALDH1low cells group, CSCs of mesenchymal origin and epithelial tumor cells (CD227+CD44+CD24- and CD44+CD24-CD49f+) are predominant. In vitro CSCs of the ALDH1low cells group expressing CD326 showed high resistance to cytostatics, CD227+ CSCs of the ALDH1hi cells group are sensitive to cytostatics. Epithelial precursors of a healthy mammary gland were revealed in normal breast tissue of patients with BC from both groups. The cells were associated with a positive effect of chemotherapy and remission in BC patients. Thus, dynamic control of their presence in blood and assessment of the sensitivity of CSCs to cytostatics in vitro can improve the effectiveness of chemotherapy in BC.