Regional evaluation of glyphosate pollution in the minor irrigation network

Due to its low cost, its ease of use and to the "mild action" declared for long time by the Control and Approval Agencies towards it, the herbicide Glyphosate, is one of the currently best-selling and most-used agricultural products worldwide. In this work, we evaluated the presence and spread of Glyphosate in the Po River Basin (Northern Italy), one of the regions with the most intensified agriculture in Europe and where, by now for decades, a strong and general loss of aquatic biodiversity is observed. In order to carry out a more precise study of the real presence of this herbicide in the waters, samples were collected from the minor water network for two consecutive years, starting in 2022, at an interval time coinciding with those of the spring and summer crop treatments. In contrast to the sampling strategies generally adopted by Environmental Protection Agencies, a more focused sampling strategy was adopted to highlight the possible high concentrations in minor watercourses in direct contact with cultivated fields. Finally, we investigated the possible consequences that the higher amounts of Glyphosate found in our monitoring activities can have on stress reactions in plant (Groenlandia densa) and animal (Daphnia magna) In all the monitoring campaigns we detected exceeding European Environmental Quality Standard - EQS limits (0.1 μg/L) values. Furthermore, in some intensively agricultural areas, concentrations reached hundreds of μg/L, with the highest peaks during spring. In G. densa and D. magna, the exposition to increasing doses of herbicide showed a clear response linked to metabolic stress. Overall, our results highlight how, after several decades of its use, the Glyphosate use efficiency is still too low, leading to economic losses for the farm and to strong impacts on ecosystem health. Current EU policy indications call for an agroecological approach necessary to find alternatives to chemical weed control, which farms can develop in different contexts in order to achieve the sustainability goals set by the Farm to Fork strategy.

Melanoma and epigenetic treatment: past and future

Melanoma is the most aggressive form of skin cancer and advanced stages are inevitably resistant to conventional therapeutic agents. In particular, epigenetic strategies might open interesting new perspectives in combination with conventional ones. Current therapeutic strategies, in particular for metastatic melanoma, do not give great results in terms of survival. Herein, I review HDACis and microRNAs for melanoma. A critical discussion of all the recent findings on this topic is also included. In my view, further studies are needed to understand the toxicity of these treatments in order to improve survival of melanoma patients.

Thoughts about cancer stem cells in solid tumors

Cancer chemotherapy efficacy is frequently impaired by either intrinsic or acquired tumor resistance. A fundamental problem in cancer research is identifying the cell type that is capable of sustaining neoplastic growth and its origin from normal tissue cells. In recent years, the cancer stem cell (CSC) theory has changed the classical view of tumor growth and therefore the therapeutic perspective. Overcoming intrinsic and acquired resistance of cancer stem/progenitor cells to current clinical treatments represents a major challenge in treating and curing the most aggressive and metastatic cancers. On the other hand, the identification of CSCs in vivo and in vitro relies on specific surface markers that should allow the sorting cancer cells into phenotypically distinct subpopulations. In the present review, recent papers published on CSCs in solid tumors (breast, prostate, brain and melanoma) are discussed, highlighting critical points such as the choice of markers to sort CSCs and mouse models to demonstrate that CSCs are able to replicate the original tumor. A discussion of the possible role of aldehyde dehydrogenase and CXCR6 biomarkers as signaling molecules in CSCs and normal stem cells is also discussed. The author believes that efforts have to be made to investigate the functional and biological properties of putative CSCs in cancer. Developing diagnostic/prognostic tools to follow cancer development is also a challenge. In this connection it would be useful to develop a multidisciplinary approach combining mathematics, physics and biology which merges experimental approaches and theory. Biological models alone are probably unable to resolve the problem completely.

Abstract 5143: ABCG2 is involved in self renewal of melanoma cancer/initiating cells and major tumor associated antigens are expressed by ABCG2-positive cells

The present model of cancer stem cells (CSC) states that tumors contain a subset of cells capable of self renewing and generating a differentiated progeny. Like normal adult tissue stem cells, CSCs account for a minor tumor cell population being the only capable of maintaining indefinite tumor growth. In melanoma, initiating/stem cells have been recently identified (melanoma CSC, MCSC). In particular, our group characterized MCSC using markers CD133 and ABCG2, a member of the ABC transporter family involved in drug resistance.

Being MCSC the best potential target of therapeutic intervention, herein we have addressed two critical questions: 1) Is ABCG2 involved in MCSC self renewal? 2) Can Tumor Associated Antigens (TAA), currently utilized as target in melanoma immunotherapeutic protocols, be used to target ABCG2-positive (ABCG2+) MCSC?

We have used as in vitro model two melanoma cell lines, IgR39 and IgR37, obtained from the primary and from metastatic lesions of the same patient, respectively. Both of these cell lines are tumorigenic when injected into NOD-SCID mice.

To address the first question, we have sorted ABCG2+ IgR39 and IgR37 cells, demonstrating an increase in the overall tumor mass by 3.00 and 1.75 fold, respectively, as compared to both ABCG2- and WT (WildType) cells. Interestingly, ABCG2+ and WT derived tumors resulted in the same weight. Then we have analyzed the level of expression of ABCG2 in tumor xenografts. According to our previous results, the level of expression of ABCG2 in both IgR39 and IgR37 tumor xenografts were undetectable. Immunohistochemistry analysis further confirmed these tumors expressed melanocyte differentiation markers such as the melanoma associated proteoglycan and HLA class I antigens at high level. HER3 and CD9 were weakly expressed. Among the Cancer Testis Antigens (CTA) NY-ESO-1 was undetectable, while MART-1 expression was documented.

To investigate the second question, RT-PCR analyses for TAA expression were performed. An overlap in the expression profile of the investigated TAA belonging to the CTA family (MAGE-A1, -A2, -A3, -A6, GAGE 1-2, GAGE 1-6, SSX-2, SSX 1-5, and NY-ESO-1) and of HMW-MAA, was observed at mRNA level between ABCG2+ and ABCG2- cells derived from the same parental cell cultures. In addition, the treatment with the DNA hypomethylating agent 5-aza-2′-deoxycytidine was able to induce a de novo expression of MAGE-A3, MAGE-A4, GAGE 1-2, GAGE 1-6 and SSX 1-5 in both ABCG2+ and ABCG2- melanoma cells derived from the same parental cell culture.

All together these results support the role of ABCG2 in self renewal in MCSC, and suggest the potential clinical effectiveness of TAA-based immunotheraputic strategies, alone or combined with DNA hypomethylating drugs, for more effective eradication of MCSC and non-MCSC neoplastic cells in patients with cutaneous melanoma.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5143.

Targeting cancer stem cells to modulate alternative vascularization mechanisms

Recently, many papers have shown that tumor vascularization can be explained by angiogenesis, recruitment, cooption, vasculogenic mimicry and by mosaic vessels. In particular, vasculogenic mimicry seems to be different from mosaic blood vessels, where tumor cells form a part of the surface of the vessel while the remaining part is covered by endothelium. In this case, tumor cells in apparent contact with the lumen do not show an endothelial phenotype. More recently, vasculogenic mimicry was proposed to occur in patients with multiple myeloma due to bone marrow macrophages. Herein, all these data are, for the first time, discussed critically in comparison to cancer stem cells-which show high trans-differentiative capacity-and bone-marrow derived stem cells. In fact, the presence of alternative vasculogenic patterns might be due to the presence of stem cell population (cancer stem cells or bone-marrow stem cells). In this connection, the literature is discussed extensively and possible models are proposed. Pharmacological perspectives will also discuss.