Hyaluronic acid (HA) plays a crucial role in tumor growth and invasion through its interaction with cluster of differentiation 44 (CD44), a non-kinase transmembrane glycoprotein, among other hyaladherins. CD44 expression is elevated in many solid tumors, and its interaction with HA is associated with cancer and angiogenesis. Despite efforts to inhibit HA-CD44 interaction, there has been limited progress in the development of small molecule inhibitors. As a contribution to this endeavour, we designed and synthesized a series of N-aryltetrahydroisoquinoline derivatives based on existing crystallographic data available for CD44 and HA. Hit 2e was identified within these structures for its antiproliferative effect against two CD44⁺ cancer cell lines, and two new analogs (5 and 6) were then synthesized and evaluated as CD44-HA inhibitors by applying computational and cell-based CD44 binding studies. Compound 2-(3,4,5-trimethoxybenzyl)-1,2,3,4-tetrahydroisoquinolin-5-ol (5) has an EC₅₀ value of 0.59 μM against MDA-MB-231 cells and is effective to disrupt the integrity of cancer spheroids and reduce the viability of MDA-MB-231 cells in a dose-dependent manner. These results suggest lead 5 as a promising candidate for further investigation in cancer treatment.

Hyaluronic acid (HA), through its interactions with the cluster of differentiation 44 (CD44), acts as a potent modulator of the tumor microenvironment, creating a wide range of extracellular stimuli for tumor growth, angiogenesis, invasion, and metastasis. An innovative antitumor treatment strategy based on the development of a nanodevice for selective release of an inhibitor of the HA-CD44 interaction is presented. Computational analysis was performed to evaluate the interaction of the designed tetrahydroisoquinoline-ketone derivative (JE22) with CD44 binding site. Cell viability, efficiency, and selectivity of drug release under acidic conditions together with CD44 binding capacity, effect on cell migration, and apoptotic activity were successfully evaluated. Remarkably, the conjugation of this CD44 inhibitor to the nanodevice generated a reduction of the dosis required to achieve a significant therapeutic effect.

A series of 11 new substituted 1,5-dihydro-4,1-benzoxazepine derivatives was synthesised to study the influence of the methyl group in the 1-(benzenesulphonyl) moiety, the replacement of the purine by the benzotriazole bioisosteric analogue, and the introduction of a bulky substituent at position 6 of the purine, on the biological effects. Their inhibition against isolated HER2 was studied and the structure–activity relationships have been confirmed by molecular modelling studies. The most potent compound against isolated HER2 is 9a with an IC₅₀ of 7.31 µM. We have investigated the effects of the target compounds on cell proliferation. The most active compound (7c) against all the tumour cell lines studied (IC₅₀ 0.42–0.86 µM) does not produce any modification in the expression of pro-caspase 3, but increases the caspase 1 expression, and promotes pyroptosis. Graphical Abstract

Aim: To develop and characterize bozepinib-loaded lipid-core nanocapsules (BZP-LNC+) as a potential treatment for glioblastoma (GBM). Methods: Characterization of nanocapsules was performed by diam...

CD44, a cell surface glycoprotein, plays a crucial role in cancer progression by enhancing cell proliferation and resistance to apoptosis. Targeting CD44 with small molecules is a promising cancer therapy strategy. Building on our previous work with the tetrahydroisoquinoline (THIQ) derivative SRT1, we designed and synthesized a series of analogues (SRT2-SRT10) to explore their anticancer potential. Among these, the sulfonate esters SRT5 and SRT6 were the most promising in CD44⁺ MDA-MB-231 breast cancer cells. They effectively inhibited the HA-CD44 interaction, as demonstrated by binding assays and cell viability studies. In addition, molecular dynamics simulations predict that these esters interact with the same key residues within the CD44-HABD domain as those involved in HA recognition. In CD44⁺ lung cancer cell lines (A549 and NCI-H23), SRT1 exhibited the strongest antiproliferative activity (EC₅₀ = 0.88 and 0.42 μM, respectively), while SRT5 and SRT6 also showed significant efficacy, particularly in NCI-H23 cells. Interestingly, only SRT1 induced apoptosis, suggesting distinct mechanisms of cell death. Kinase profiling revealed that SRT5 and SRT6 inhibited CD44-associated kinases, particularly SRC, contributing to their anticancer effects. In contrast, SRT1 appeared to act through a kinase-independent pathway. All compounds displayed high selectivity for cancer cells over non-tumoral lung cells. ADME predictions suggested favorable pharmacokinetic properties. Overall, our results underscore the potential of N-benzylTHIQ derivatives, as selective agents for targeted therapy of lung cancer and support further in vivo validation and mechanistic investigations.

Molecular interactions at the cell surface, in particular between hyaluronic acid (HA) and the cluster of differentiation 44 (CD44) receptor, are crucial in several biological processes and diseases such as cancer. Thus, inhibition of the HA-CD44 interaction has become a promising therapeutic strategy. Etoposide was the only antitumor compound known to inhibit the binding of CD44 to HA, thereby disrupting key functions that drive malignancy. However, our recent research led to the development of N-alkyl and N-aryl THIQ derivatives, which represented a significant advancement in this field. Here, we further explore the structure-activity relationships of a series of newly designed N-alkylcarbonyl THIQ and study the structural parameters that define both the CD44 inhibitory and antiproliferative activities. Compounds 5d and 7d showed the most improvement of the antiproliferative activity compared to the N-alkylketone 1. Cell viability, competitive binding assays and molecular dynamics studies demonstrated effective inhibition of HA-CD44 binding by compounds 5d and 7d. This work not only expands the arsenal of potential therapeutic agents targeting HA-CD44 interactions but also highlights the potential for new treatments that could more effectively disrupt cancer progression.