RAL GTPases mediate multiple myeloma cell survival and are activated independently of oncogenic RAS.

Oncogenic RAS provides crucial survival signaling for up to half of multiple myeloma cases, but has so far remained a clinically undruggable target. RAL is a member of the RAS superfamily of small GTPases and is considered to be a potential mediator of oncogenic RAS signaling. In primary multiple myeloma, we found RAL to be overexpressed in the vast majority of samples when compared with pre-malignant monoclonal gammopathy of undetermined significance or normal plasma cells. We analyzed the functional effects of RAL abrogation in myeloma cell lines and found that RAL is a critical mediator of survival. RNAi-mediated knockdown of RAL resulted in rapid induction of tumor cell death, an effect which was independent from signaling via mitogen-activated protein kinase, but appears to be partially dependent on Akt activity. Notably, RAL activation was not correlated with the presence of activating RAS mutations and remained unaffected by knockdown of oncogenic RAS. Furthermore, transcriptome analysis yielded distinct RNA expression signatures after knockdown of either RAS or RAL. Combining RAL depletion with clinically relevant anti-myeloma agents led to enhanced rates of cell death. Our data demonstrate that RAL promotes multiple myeloma cell survival independently of oncogenic RAS and, thus, this pathway represents a potential therapeutic target in its own right.

Increase of the T-reg-recruiting chemokine CCL22 expression in a progressive course of cervical dysplasia.

PURPOSE: An increasing infiltration of FoxP3-positive T-regs is associated with a higher grade of cervical intraepithelial neoplasia. The T-reg-recruiting chemokine CCL22 is expressed in various tumour entities. Aim of our study was to investigate the role of CCL22 in the progression and regression of cervical intraepithelial neoplasias, especially in patients with intermediate cervical intraepithelial neoplasias (CIN II). Furthermore, our aim was to characterize the CCL22-producing cells and explore the role of innate immunity in the process of cells recruitment. METHODS: CCL22 expression was analyzed immunohistochemically in 169 patient samples. The immunoreactive score as well as the median numbers of positive cells were calculated in each slide and correlated with the histological CIN grade and FoxP3 expression. Additionally, CD68/CCL22 as well as CD68/PPARγ and CD68/FoxP3 expression were examined by double immunofluorescence. Statistical analysis was performed by SPSS 26. RESULTS: A significantly higher expression of epithelial CCL22 in CIN II with progression in comparison to CIN II with regression (p = 0.006) could be detected. CCL22 was correlated with FoxP3 (Spearman's Rho: 0.308; p < 0.01). In 88%, CCL22-positive cells were positive for CD68, and 71% of CD68-positive macrophages expressed PPARγ. Colocalization of CD68 and FoxP3 was detected in 12%. CONCLUSION: We could demonstrate that increased expression of CCL22, mainly produced by macrophages, correlates with elevated potential of malignancy. CCL22 expression could act as a predictor for regression and progression in cervical intraepithelial neoplasia, and it may help in the decision process regarding surgical treatment versus watchful waiting strategy in order to prevent conisation-associated risks. Furthermore, our findings support the potential of CCL22-producing cells as a target for immune therapy in cervical cancer patients.

Role of FoxP3-positive regulatory T-cells in regressive and progressive cervical dysplasia.

PURPOSE: Forkhead Box Protein 3 (FoxP3) is known as a key mediator in the immunosuppressive function of regulatory T-cells (Tregs). The aim of our study was to investigate whether FoxP3-positive Tregs have the potential to act as an independent predictor in progression as well as in regression of cervical intraepithelial neoplasia, especially in patients with intermediate cervical intraepithelial neoplasia (CIN II). METHODS: Nuclear FoxP3 expression was immunohistochemically analysed in 169 patient samples (CIN I, CIN II with regressive course, CIN II with progressive course, CIN III). The median numbers were calculated for each slide and correlated with the histological CIN grade. Statistical analysis was performed by SPSS 26 (Mann-Whitney U test, Spearman's rank correlation). RESULTS: An increased FoxP3 expression in CIN II with progression could be detected in comparison to CIN II with regression (p = 0.003). Total FoxP3 expression (epithelium and dysplasia-connected stroma) was higher in more advanced CIN grades (p < 0.001 for CIN I vs. CIN II; p = 0.227 for CIN II vs. CIN III). A positive correlation could be detected between FoxP3-positive cells in epithelium and total FoxP3 expression (Spearman's Rho: 0,565; p < 0.01). CONCLUSION: Expression of FoxP3 could be a helpful predictive factor to assess the risks of CIN II progression. As a prognosticator for regression and progression in cervical intraepithelial lesions it might thereby help in the decision process regarding surgical treatment vs. watchful waiting strategy to prevent conisation-associated risks for patients in child-bearing age. In addition, the findings support the potential of Tregs as a target for immune therapy in cervical cancer patients.