Paola Orlandi

Cyclin-Dependent Kinase 4/6 inhibitors (CDK 4/6i) represented a paradigm shift in the treatment of patients with metastatic hormone-receptor-positive (HR+), HER2-negative (HER2-) breast cancer patients. When disease progression occurs and further hormonal manipulations or target therapies fail, chemotherapy remains a therapeutic choice. For these reasons, resources should be invested in redesigning the best treatment strategy with the current chemotherapy drugs available. Nevertheless, the preferred strategy typically remains a planned sequence of single chemotherapeutic agents. This approach endeavors to extend overall survival and maintain quality of life. Within this complex and evolving therapeutic scenario, where the necessity for effective and treatment options is crucial, we explore in the present paper a perspective for a hypothetical new role of bevacizumab combined with paclitaxel for patients with metastatic HR+, HER2- breast cancer patients resistant to hormone therapy. Recent findings from our preliminary published pharmacogenetic studies, could suggest the efficacy of bevacizumab as linked to a well-defined genomic profile of genes implicated in the process of neoangiogenesis (e.g., favorable profile: VEGF-A rs833061/VEGFR-2 rs1870377: CT/AT, CT/AA, TT/AA, TT/TT, CC/TT), concluding the present perspective underlying the fact that bevacizumab combined with paclitaxel will be reconsidered with this new potential use only if well-designed prospective trials confirm what has been observed from our retrospective data.

Background/Objectives: Metronomic chemotherapy offers a well-tolerated option for heavily pretreated metastatic gastrointestinal cancer patients, but reliable prognostic biomarkers for patient selection are lacking. This study aimed to identify exploratory circulating cytokine signatures associated with outcomes in patients treated with metronomic chemotherapy. Methods: We analyzed plasma samples from 34 patients enrolled in the COMET trial (EudraCT 2007-000065-38), a phase II study of metronomic UFT, cyclophosphamide, and celecoxib. An 88-cytokine Luminex^® (Luminex Corporation, Austin, TX, USA) panel was measured at baseline and at four treatment timepoints. Partial least squares discriminant analysis identified candidate biomarkers, followed by systematic combinatorial analysis using Manciu’s method to construct 3-cytokine composite risk scores. Results: Twenty-one patients (61.8%) experienced progressive disease and 13 (38.2%) achieved stable disease. Six biomarkers showed significant discriminative power: IL-16, MCP-4, THBS-2, Eotaxin-1, PDGF-AB/BB, and TRAIL. Three 3-cytokine panels achieved statistically significant risk stratification (all p < 0.05), with hazard ratios for overall survival ranging from 2.59 to 6.24. For the representative IL-16 + MCP-4 + THBS-2 panel, high-risk patients showed a median PFS of 2.0 vs. 4.0 months (HR 3.24, p = 0.0046) and a median OS of 5.8 vs. 11.1 months (HR 4.19, p = 0.0010). Conclusions: This exploratory pharmacodynamic biomarker analysis identifies three 3-cytokine panels associated with prognostic risk stratification in metronomic chemotherapy for metastatic gastrointestinal cancer. As this single-arm trial cannot distinguish prognostic from predictive value, findings are hypothesis-generating. Prospective external validation is required before clinical translation, and exploration in combination with immune checkpoint inhibitors is warranted.

Background: Mesangiogenic Progenitor cells (MPCs) were first described in 2008 in cultures of human bone marrow mononuclear cells (hBM-MNCs) aimed at isolating mesenchymal stromal cells (MSCs) using human autologous serum. A selective culture method was subsequently developed to isolate MPCs with a high degree of purity, yielding approximately 1% of the total plated cells. Since their initial description, MPCs have demonstrated the ability to differentiate into highly clonogenic MSCs while retaining early vasculogenic potential. Gene expression profiling of MPCs revealed constitutive expression of pluripotency-associated transcription factors such as OCT-4 and NANOG, as well as SOX15 instead of SOX2, suggesting a possible molecular mechanism that sustains MPC plasticity, defined as the “adult Oct-4 circuit”. Although the expression of these pluripotency-associated markers has been hypothesized to represent a distinctive adult molecular circuit, concerns regarding the tumorigenic potential of MPCs are reasonable and have not yet explored. Methods: Here, we present data from the tumorigenicity test in partial compliance with WHO recommendations of two different MPC-derived cell products in athymic nude mice. Results: Histomorphometric analysis of nodules excised from animals at 6, 8, or 12 weeks post-cell transplantation excluded tumor formation and demonstrated the ability of MPCs to generate homogeneous and organized tissue through distinct phases: an “early” vasculogenic phase, followed by remodeling of the newly formed microvascular network and the deposition of structured, aligned collagen fibers. Conclusions: MPCs do not possess intrinsic tumorigenic potential and spontaneously form vascularized xenogenic tissue four weeks after injection into the subcutaneous space.

Background/Objectives MC4R expression and its role in colorectal and anaplastic thyroid cancers, where resistance to therapy and lack of standard treatments remain significant challenges, are poorly understood. This study aimed to investigate MC4R as a potential therapeutic target in these cancers using the selective antagonist ML00253764 (ML), alone and in combination with vinorelbine (VNR) and irinotecan (or its active metabolite SN-38). Methods: Human colorectal adenocarcinoma HT-29, Caco-2, and anaplastic thyroid carcinoma 8305C cell lines were used. MC4R expression was assessed by Real-Time PCR with validated primers (Assay ID Hs00271877_s1), immunofluorescence, and Western blotting. Proliferation and apoptosis assays were conducted with ML, and synergy with VNR and SN-38 was evaluated by Combination Index and Loewe methods. ERK1/2 phosphorylation was measured using an ELISA assay. In vivo studies were conducted by injecting tumor cells into Athymic Nude-Foxn1nu mice, treated with ML, VNR, irinotecan, or their combinations. Results: MC4R expression was confirmed in all cell lines. ML treatment inhibited MC4R, producing antiproliferative and pro-apoptotic effects, with IC₅₀ values of 7667 ± 2144.6 nM (8305C), 806.4 ± 321.8 nM (HT-29), and 2993 ± 1135.2 nM (Caco-2). In combination with VNR and SN-38, ML exhibited significant synergy in vitro and reduced tumor volume in vivo without causing weight loss or adverse effects in mice. Conclusions This study identifies ML as a promising therapeutic agent that, when combined with chemotherapy, may offer a novel strategy for treating colorectal and anaplastic thyroid cancers.