The Hyaluronan/CD44 Axis: A Double-Edged Sword in Cancer

Antitumor activities of anti‑CD44 monoclonal antibodies in mouse xenograft models of esophageal cancer

CD44 is a type I transmembrane glycoprotein associated with poor prognosis in various solid tumors. Since CD44 plays a critical role in tumor development by regulating cell adhesion, survival, proliferation and stemness, it has been considered a target for tumor therapy. Anti‑CD44 monoclonal antibodies (mAbs) have been developed and applied to antibody‑drug conjugates and chimeric antigen receptor‑T cell therapy. Anti-pan‑CD44 mAbs, C44Mab‑5 and C44Mab‑46, which recognize both CD44 standard (CD44s) and variant isoforms were previously developed. The present study generated a mouse IgG2a version of the anti‑pan‑CD44 mAbs (5‑mG2a and C44Mab‑46‑mG2a) to evaluate the antitumor activities against CD44‑positive cells. Both 5‑mG2a and C44Mab‑46‑mG2a recognized CD44s‑overexpressed CHO‑K1 (CHO/CD44s) cells and esophageal tumor cell line (KYSE770) in flow cytometry. Furthermore, both 5‑mG2a and C44Mab‑46‑mG2a could activate effector cells in the presence of CHO/CD44s cells and exhibited complement-dependent cytotoxicity against both CHO/CD44s and KYSE770 cells. Furthermore, the administration of 5‑mG2a and C44Mab‑46‑mG2a significantly suppressed CHO/CD44s and KYSE770 xenograft tumor development compared with the control mouse IgG2a. These results indicate that 5‑mG2a and C44Mab‑46‑mG2a could exert antitumor activities against CD44‑positive cancers and be a promising therapeutic regimen for tumors.

Anti-CD44 Variant 10 Monoclonal Antibody Exerts Antitumor Activity in Mouse Xenograft Models of Oral Squamous Cell Carcinomas

CD44 regulates cell adhesion, proliferation, survival, and stemness and has been considered a tumor therapy target. CD44 possesses the shortest CD44 standard (CD44s) and a variety of CD44 variant (CD44v) isoforms. Since the expression of CD44v is restricted in epithelial cells and carcinomas compared to CD44s, CD44v has been considered a promising target for monoclonal antibody (mAb) therapy. We previously developed an anti-CD44v10 mAb, C44Mab-18 (IgM, kappa), to recognize the variant exon 10-encoded region. In the present study, a mouse IgG2a version of C44Mab-18 (C44Mab-18-mG2a) was generated to evaluate the antitumor activities against CD44-positive cells compared with the previously established anti-pan CD44 mAb, C44Mab-46-mG2a. C44Mab-18-mG2a exhibited higher reactivity compared with C44Mab-46-mG2a to CD44v3-10-overexpressed CHO-K1 (CHO/CD44v3-10) and oral squamous cell carcinoma cell lines (HSC-2 and SAS) in flow cytometry. C44Mab-18-mG2a exerted a superior antibody-dependent cellular cytotoxicity (ADCC) against CHO/CD44v3-10. In contrast, C44Mab-46-mG2a showed a superior complement-dependent cytotoxicity (CDC) against CHO/CD44v3-10. A similar tendency was observed in ADCC and CDC against HSC-2 and SAS. Furthermore, administering C44Mab-18-mG2a or C44Mab-46-mG2a significantly suppressed CHO/CD44v3-10, HSC-2, and SAS xenograft tumor growth compared with the control mouse IgG2a. These results indicate that C44Mab-18-mG2a could be a promising therapeutic regimen for CD44v10-positive tumors.

Abnormal expression of serum miR-4746-5p in liver cancer patients after interventional chemotherapy and its possible mechanism

Interventional chemotherapy is a common operation in the clinical treatment of liver cancer. The aim of this study was to investigate the expression and molecular mechanism of serum miR-4746-5p in liver cancer patients before and after interventional chemotherapy. The levels of miR-4746-5p and CDKN1C in serum samples from liver cancer patients were detected using real-time fluorescence quantitative polymerase chain reaction. Receiver operating characteristic curves revealed the diagnostic value of miR-4746-5p in tumors. Differences in clinical indicators between liver cancer patients and healthy controls were assessed using Pearson correlation analysis. Luciferase reporter gene assays confirmed the targeted interaction between miR-4746-5p and CDKN1C. In vitro cellular assays were validated by Cell Counting Kit-8, Transwell assay, and chemoresistance assay. Serum miR-4746-5p levels were increased in liver cancer patients but were downregulated after chemotherapy intervention. CDKN1C expression showed the opposite trend. Low levels of miR-4746-5p mediated cell growth and metastasis by targeting and negatively regulating CDKN1C expression, while silencing CDKN1C restored cell activity. Inhibition of miR-4746-5p reduced chemoresistance, while downregulation of CDKN1C affected cell sensitivity. miR-4746-5p may be a potential therapeutic factor for liver cancer diagnosis and interventional chemotherapy.

The Tumor Stroma of Squamous Cell Carcinoma: A Complex Environment That Fuels Cancer Progression

The tumor microenvironment (TME), a complex assembly of cellular and extracellular matrix (ECM) components, plays a crucial role in driving tumor progression, shaping treatment responses, and influencing metastasis. This narrative review focuses on the cutaneous squamous cell carcinoma (cSCC) tumor stroma, highlighting its key constituents and their dynamic contributions. We examine how significant changes within the cSCC ECM-specifically, alterations in fibronectin, hyaluronic acid, laminins, proteoglycans, and collagens-promote cancer progression, metastasis, and drug resistance. The cellular composition of the cSCC TME is also explored, detailing the intricate interplay of cancer-associated fibroblasts (CAFs), mesenchymal stem cells (MSCs), endothelial cells, pericytes, adipocytes, and various immune cell populations. These diverse players modulate tumor development, angiogenesis, and immune responses. Finally, we emphasize the TME's potential as a therapeutic target. Emerging strategies discussed in this review include harnessing the immune system (adoptive cell transfer, checkpoint blockade), hindering tumor angiogenesis, disrupting CAF activity, and manipulating ECM components. These approaches underscore the vital role that deciphering TME interactions plays in advancing cSCC therapy. Further research illuminating these complex relationships will uncover new avenues for developing more effective treatments for cSCC.

UDP-glucose dehydrogenase supports autophagy-deficient PDAC growth via increasing hyaluronic acid biosynthesis

Autophagy is an essential degradation and recycling process that maintains cellular homeostasis during stress or nutrient deprivation. However, certain types of tumors such as pancreatic cancers can circumvent autophagy inhibition to sustain growth. The mechanism that autophagy-deficient pancreatic ductal adenocarcinoma (PDAC) uses to grow under nutrient deprivation is poorly understood. Our data show that nutrient deprivation in PDAC results in UDP-glucose dehydrogenase (UGDH) degradation, which is dependent on autophagic cargo receptor sequestosome 1 (p62). Moreover, we demonstrate that accumulated UGDH is indispensable for autophagy-deficient PDAC cells proliferation by promoting hyaluronic acid (HA) synthesis upon energy deprivation. Using an orthotopic mouse model of PDAC, we find that inhibition of HA synthesis by targeting UGDH in PDAC reduces tumor weight. Thus, the combined inhibition of HA and autophagy might be an attractive strategy for PDAC treatment.

Precision targeting in hepatocellular carcinoma: Exploring ligand-receptor mediated nanotherapy

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and poses a major challenge to global health due to its high morbidity and mortality. Conventional chemotherapy is usually targeted to patients with intermediate to advanced stages, but it is often ineffective and suffers from problems such as multidrug resistance, rapid drug clearance, nonspecific targeting, high side effects, and low drug accumulation in tumor cells. In response to these limitations, recent advances in nanoparticle-mediated targeted drug delivery technologies have emerged as breakthrough approaches for the treatment of HCC. This review focuses on recent advances in nanoparticle-based targeted drug delivery systems, with special attention to various receptors overexpressed on HCC cells. These receptors are key to enhancing the specificity and efficacy of nanoparticle delivery and represent a new paradigm for actively targeting and combating HCC. We comprehensively summarize the current understanding of these receptors, their role in nanoparticle targeting, and the impact of such targeted therapies on HCC. By gaining a deeper understanding of the receptor-mediated mechanisms of these innovative therapies, more effective and precise treatment of HCC can be achieved.

Relationship between immune checkpoint proteins and neoadjuvant chemotherapy response in breast cancer

INTRODUCTION

Following major developments in cancer immunotherapy, treatments targeting immune checkpoint proteins (ICP) gained interest in breast cancer, though studies mostly focus on patients with metastatic disease as well as patients nonresponsive to the conventional treatments. Herein, we aimed to investigate the levels of ICP in tumor stroma and tumor infiltrating lymphocytes, and tumor tissue prior to neoadjuvant chemotherapy administration to evaluate the relationship between ICP levels, clinicopathological parameters, and NAC response.

MATERIALS AND METHODS

This study was conducted with 51 patients where PD-1, PD-L1, CTLA-4, TIM-3, CD24 and CD44 levels were investigated in CD45+ cells while CD326, CD24, CD44 and PD-L1 protein expression levels were investigated in CD45- population. In addition, CD44 and CD24 levels were evaluated in the tumor stroma. TIL levels were investigated according to the TILS Working Group. Treatment responses after NAC were evaluated according to the MD Anderson RCB score.

RESULTS

Our results revealed positive correlation between CTLA-4 and CD44 expression in cases with high TIL levels as well as TIL levels and CTLA-4 expression in cases with partial response. Similarly, positive correlation was detected between TIM3 and PD-L1 levels in cases with good response. In addition, a negative correlation between TILs after NAC and PD-1/PD-L1 expression in lymphocytes in cases with partial complete response.

CONCLUSIONS

Our study provides preliminary data about the correlation between ICP and clinicopathological status and NAC response in breast cancer, in addition to underlining the requirement for further research to determine their potential as therapeutic targets.