Disruption of the pentraxin 3/CD44 interaction as an efficient therapy for triple-negative breast cancers.

Due to the heterogeneity and high frequency of genome mutations in cancer cells, targeting vital protumour factors found in stromal cells in the tumour microenvironment may represent an ideal strategy in cancer therapy. However, the regulation and mechanisms of potential targetable therapeutic candidates need to be investigated. An in vivo study demonstrated that loss of pentraxin 3 (PTX3) in stromal cells significantly decreased the metastasis and growth of cancer cells. Clinically, our results indicate that stromal PTX3 expression correlates with adverse prognostic features and is associated with worse survival outcomes in triple-negative breast cancer (TNBC). We also found that transforming growth factor beta 1 (TGF-ß1) induces PTX3 expression by activating the transcription factor CCAAT/enhancer binding protein delta (CEBPD) in stromal fibroblasts. Following PTX3 stimulation, CD44, a PTX3 receptor, activates the downstream ERK1/2, AKT and NF-κB pathways to specifically contribute to the metastasis/invasion and stemness of TNBC MDA-MB-231 cells. Two types of PTX3 inhibitors were developed to disrupt the PTX3/CD44 interaction and they showed a significant effect on attenuating growth and restricting the metastasis/invasion of MDA-MB-231 cells, suggesting that targeting the PTX3/CD44 interaction could be a new strategy for future TNBC therapies.

Specific expression of survivin, SOX9, and CD44 in renal tubules in adaptive and maladaptive repair processes after acute kidney injury in rats.

Acute kidney injury (AKI) is thought to be a reversible condition; however, growing evidence has suggested that AKI may be associated with subsequent development of chronic kidney disease. Although renal tubules have intrinsic regeneration capacity, disruption of the regeneration mechanisms leads to irreversible interstitial fibrosis. In this study, we investigated immunohistochemical markers of renal tubules in adaptive and maladaptive repair processes to predict AKI reversibility. Histopathological analysis demonstrated that regenerative tubules and dilated tubules were observed in the kidneys of AKI model rats after ischemia/reperfusion (I/R). Regenerative tubules gradually redifferentiated after I/R, whereas dilated tubules exhibited no tendency for redifferentiation. In fibrotic areas of the kidney in renal fibrosis model rats subjected to I/R, renal tubules were dilated or atrophied. There results suggested that the histopathological features of renal tubules in the maladaptive repair were dilation or atrophy. From microarray data of regenerative tubules, survivin, SOX9, and CD44 were extracted as candidate markers. Immunohistochemical analysis demonstrated that survivin and SOX9 were expressed in regenerative tubules, whereas SOX9 was also detected in renal tubules in fibrotic areas. These findings indicated that survivin and SOX9 contributed to renal tubular regeneration, whereas sustained SOX9 expression may be associated to fibrosis. CD44 was expressed in dilated tubules in the kidneys of AKI model rats and in the tubules of fibrotic areas of renal fibrosis model rats, suggesting that CD44 was expressed in renal tubules in maladaptive repair. Thus, these factors could be useful markers for detecting disruption of the regenerative mechanisms of renal tubules.

CD44/HA signaling mediates acquired resistance to a PI3Kα inhibitor.

Most luminal breast carcinomas (BrCas) bearing PIK3CA mutations initially respond to phosphoinositide-3-kinase (PI3K)-α inhibitors, but many eventually become resistant. The underlying mechanisms of this resistance remain obscure. In this work, we showed that a CD44high state due to aberrant isoform splicing was acquired from adaptive resistance to a PI3Kα inhibitor (BLY719) in luminal BrCas. Notably, the expression of CD44 was positively correlated with estrogen receptor (ER) activity in PIK3CA-mutant breast cancers, and ER-dependent transcription upon PI3Kα pathway inhibition was in turn mediated by CD44. Furthermore, the interaction of CD44 with the ligand hyaluronan (HA) initiated the Src-ERK signaling cascade, which subsequently maintained AKT and mTOR activity in the presence of a PI3Kα inhibitor. Activation of this pathway was prevented by disruption of the CD44/HA interaction, which in turn restored sensitivity to BLY719. Our results revealed that an ER-CD44-HA signaling circuit that mediates robust compensatory activation of the Src-ERK signaling cascade may contribute to the development of acquired resistance to PI3Kα inhibitors. This study provides new insight into the mechanism of adaptive resistance to PI3Kα inhibition therapy.

Effects of Apatinib on the "Stemness" of Non-Small-Cell Lung Cancer Cells In Vivo and Its Related Mechanisms.

Objective: To investigate the effects of Apatinib on the "stemness" of lung cancer cells in vivo and to explore its related mechanisms. Methods: A xenograft model of lung cancer cells A549 was established in nude mice and randomized into a control group (n = 4) and an Apatinib group (n = 4). Tumor tissues were harvested after 2 weeks, and mRNA was extracted to detect changes in stemness-related genes (CD133, EPCAM, CD13, CD90, ALDH1, CD44, CD45, SOX2, NANOG, and OCT4) and Wnt/ß-catenin, Hedgehog, and Hippo signal pathways. Results: Compared with the control group, the volume and weight of nude mice treated with Apatinib were different and had statistical significance. Apatinib inhibited the expressions of ABCG2, CD24, ICAM-1, OCT4, and SOX2 and upregulated the expressions of CD44, CD13, and FOXD3. Apatinib treatment also inhibited the Wnt/ß-catenin, Hedgehog, and Hippo signaling pathways. Conclusion: Apatinib suppressed the growth of non-small-cell lung cancer cells by repressing the stemness of lung cancer through the inhibition of the Hedgehog, Hippo, and Wnt signaling pathways.

Hyaluronic Acid (HA) Receptors and the Motility of Schwann Cell(-Like) Phenotypes.

The cluster of differentiation 44 (CD44) and the hyaluronan-mediated motility receptor (RHAMM), also known as CD168, are perhaps the most studied receptors for hyaluronic acid (HA); among their various functions, both are known to play a role in the motility of a number of cell types. In peripheral nerve regeneration, the stimulation of glial cell motility has potential to lead to better therapeutic outcomes, thus this study aimed to ascertain the presence of these receptors in Schwann cells (rat adult aSCs and neonatal nSCs) and to confirm their influence on motility. We included also a Schwann-like phenotype (dAD-MSCs) derived from adipose-derived mesenchymal stem cells (uAD-MSCs), as a possible basis for an autologous cell therapy. CD44 was expressed similarly in all cell types. Interestingly, uAD-MSCs were RHAMM(low), whereas both Schwann cells and dASCs turned out to be similarly RHAMM(high), and indeed antibody blockage of RHAMM effectively immobilized (in vitro scratch wound assay) all the RHAMM(high) Schwann(-like) types, but not the RHAMM(low) uAD-MSCs. Blocking CD44, on the other hand, affected considerably more uAD-MSCs than the Schwann(-like) cells, while the combined blockage of the two receptors immobilized all cells. The results therefore indicate that Schwann-like cells have a specifically RHAMM-sensitive motility, where the motility of precursor cells such as uAD-MSCs is CD44- but not RHAMM-sensitive; our data also suggest that CD44 and RHAMM may be using complementary motility-controlling circuits.

Enhanced cytotoxicity of a redox-sensitive hyaluronic acid-based nanomedicine toward different oncocytes via various internalization mechanisms.

Receptor-mediated active targeting and tumor microenvironment responsive systems from polymeric micelles have been studied for rapid cellular internalization and triggered drug release. Previously we have constructed redox-responsive polymeric micelles composed of vitamin E succinate conjugated hyaluronic acid (HA-ss-TOS), which are able to actively target CD44 proteins and quickly release loaded drugs upon exposure to high levels of glutathione (GSH) in tumor cells. In the present study, we found that despite different cellular internalization mechanisms, micelles showed strong antineoplastic effects on 4T1 and B16F10 cells due to redox responsiveness. HA-ss-TOS-PTX micelles exhibited an excellent tumor targeting ability and prolonged retention time compared to Taxol in vivo. In addition, a superior antitumor effect was achieved compared to PTX-loaded insensitive micelles (HA-TOS-PTX) and Taxol. Our results revealed that PTX-loaded HA-ss-TOS micelles could enhance the antineoplastic efficacy of PTX for breast cancer and melanoma treatment and, thus, deserve further attention.

FKBPL-based peptide, ALM201, targets angiogenesis and cancer stem cells in ovarian cancer.

BACKGROUND: ALM201 is a therapeutic peptide derived from FKBPL that has previously undergone preclinical and clinical development for oncology indications and has completed a Phase 1a clinical trial in ovarian cancer patients and other advanced solid tumours. METHODS: In vitro, cancer stem cell (CSC) assays in a range of HGSOC cell lines and patient samples, and in vivo tumour initiation, growth delay and limiting dilution assays, were utilised. Mechanisms were determined by using immunohistochemistry, ELISA, qRT-PCR, RNAseq and western blotting. Endogenous FKBPL protein levels were evaluated using tissue microarrays (TMA). RESULTS: ALM201 reduced CSCs in cell lines and primary samples by inducing differentiation. ALM201 treatment of highly vascularised Kuramochi xenografts resulted in tumour growth delay by disruption of angiogenesis and a ten-fold decrease in the CSC population. In contrast, ALM201 failed to elicit a strong antitumour response in non-vascularised OVCAR3 xenografts, due to high levels of IL-6 and vasculogenic mimicry. High endogenous tumour expression of FKBPL was associated with an increased progression-free interval, supporting the protective role of FKBPL in HGSOC. CONCLUSION: FKBPL-based therapy can (i) dually target angiogenesis and CSCs, (ii) target the CD44/STAT3 pathway in tumours and (iii) is effective in highly vascularised HGSOC tumours with low levels of IL-6.

Hyaluronic Acid-Decorated Liposomes as Innovative Targeted Delivery System for Lung Fibrotic Cells.

Collagen Tissue Disease-associated Interstitial Lung Fibrosis (CTD-ILDs) and Bronchiolitis Obliterans Syndrome (BOS) represent severe lung fibrogenic disorders, characterized by fibro-proliferation with uncontrolled extracellular matrix deposition. Hyaluronic acid (HA) plays a key role in fibrosis with its specific receptor, CD44, overexpressed by CTD-ILD and BOS cells. The aim is to use HA-liposomes to develop an inhalatory treatment for these diseases. Liposomes with HA of two molecular weights were prepared and characterized. Targeting efficiency was assessed toward CTD-ILD and BOS cells by flow cytometry and confocal microscopy and immune modulation by RT-PCR and ELISA techniques. HA-liposomes were internalized by CTD-ILD and BOS cells expressing CD44, and this effect increased with higher HA MW. In THP-1 cells, HA-liposomes decreased pro-inflammatory cytokines IL-1ß, IL-12, and anti-fibrotic VEGF transcripts but increased TGF-ß mRNA. However, upon analyzing TGF-ß release from healthy donors-derived monocytes, we found liposomes did not alter the release of active pro-fibrotic cytokine. All liposomes induced mild activation of neutrophils regardless of the presence of HA. HA liposomes could be also applied for lung fibrotic diseases, being endowed with low pro-inflammatory activity, and results confirmed that higher MW HA are associated to an increased targeting efficiency for CD44 expressing LFs-derived from BOS and CTD-ILD patients.

Anti-Inflammatory Effects of Intra-Articular Hyaluronic Acid: A Systematic Review.

OBJECTIVE: Osteoarthritis (OA) is one of the leading causes of disability in the adult population. Common nonoperative treatment options include nonsteroidal anti-inflammatory drugs (NSAIDs), intra-articular corticosteroids, and intra-articular injections of hyaluronic acid (HA). HA is found intrinsically within the knee joint providing viscoelastic properties to the synovial fluid. HA therapy provides anti-inflammatory relief through a number of different pathways, including the suppression of pro-inflammatory cytokines and chemokines. METHODS: We conducted a systematic review to summarize the published literature on the anti-inflammatory properties of hyaluronic acid in osteoarthritis. Included articles were categorized based on the primary anti-inflammatory responses described within them, by the immediate cell surface receptor protein assessed within the article, or based on the primary theme of the article. Key findings aimed to describe the macromolecules and inflammatory-mediated responses associated with the cell transmembrane receptors. RESULTS: Forty-eight articles were included in this systematic review that focused on the general anti-inflammatory effects of HA in knee OA, mediated through receptor-binding relationships with cluster determinant 44 (CD44), toll-like receptor 2 (TLR-2) and 4 (TLR-4), intercellular adhesion molecule-1 (ICAM-1), and layilin (LAYN) cell surface receptors. Higher molecular weight HA (HMWHA) promotes anti-inflammatory responses, whereas short HA oligosaccharides produce inflammatory reactions. CONCLUSIONS: Intra-articular HA is a viable therapeutic option in treating knee OA and suppressing inflammatory responses. HMWHA is effective in suppressing the key macromolecules that elicit the inflammatory response by short HA oligosaccharides.

Minocycline decreases CD36 and increases CD44 in LPS-induced microglia.

Microglia are the resident macrophages patrolling the central nervous system (CNS) to find dangerous signals and infectious agents mediating catastrophic cascades resulting in neuronal degeneration. Their morphological and biochemical properties made them enable to swift activation in response to neural insults and site-directed phagocytosis. Beside of beneficial roles in homeostasis of the brain and spinal cord, microglia can be participating in neuronal destruction and propagation of inflammation when they are unregulated or hyper-activated. A large body of research indicates that various cluster of differentiations (CDs) contribute to flame/quench the inflammatory processes occurred in immune system. In this study, we investigated the expression of CD36 and CD44 in LPS-activated primary rat microglia in response to treatment of minocycline at the levels of protein and gene using flow cytometry and real-time PCR, respectively. The results showed that minocycline decreased the expression of CD36 in cells treated with minocycline with respect to cells treated with LPS. Inversely, the expression of CD44 was increased in cells treated with minocycline in comparison to LPS-induced microglia. It seems that minocycline can modulate the expression of CDs involved in inflammatory reactions and enrich the armamentarium of therapeutic agents used for the treatment of neuroinflammatory and neurodegenerative disorders.

Quercetin suppresses breast cancer stem cells (CD44+/CD24-) by inhibiting the PI3K/Akt/mTOR-signaling pathway.

AIMS: Cancer stem cells (CSCs) are considered the prime source of cancer recurrence, metastasis, and progression and represent important targets for developing novel anticancer agents and therapeutic strategies. The aim of this study was to investigate the effect of treating breast CSCs with the anticancer flavonoid, quercetin. MAIN METHODS: We examined changes in the cluster of differentiation CD44+/CD24-CSC population and behavior using the breast cancer cell line MCF-7. KEY FINDINGS: Our results indicated that cell viability, clone formation, mammosphere generation, and nude mice tumor metastasis were inhibited in the CD44+/CD24- population and that MCF-7 cells exhibited G1-phase arrest after quercetin treatment. Additionally, CyclinD1 and B cell lymphoma-2 expression were suppressed and Bcl-2-like protein-4 expression was enhanced after quercetin treatment. We also observed that estrogen receptor α and phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling were downregulated concurrently with the inhibition of CD44+/CD24- viability and clone formation. Our findings suggested that quercetin treatment promoted weaker malignant activity associated with CSCs relative to that observed in normal cancer cells through its inhibition of the PI3K/Akt/mTOR-signaling pathway. SIGNIFICANCE: These results indicated that CSCs are potential therapeutic targets for quercetin treatment of breast cancer.

The natural flavonoid apigenin sensitizes human CD44+ prostate cancer stem cells to cisplatin therapy.

Prostate cancer (PCa) is the second most common type of cancer and the fifth leading cause of cancer-related death among men. Development of chemoresistance, tumor relapse and metastasis remain major barriers to effective treatment and all been identified to be associated with cancer stem cells (CSCs). Natural flavonoids such as apigenin have been shown to have the ability to improve the therapeutic efficacy of common chemotherapy agents through CSCs sensitization. Thus, the aim of this study was to evaluate the combination of apigenin with cisplatin on CD44+ PCa stem cell growth and migration. Platinum-based anti-neoplastic drugs have been used to treat a number of malignancies including PCa. However, acquired resistance and side effects unfortunately have limited cisplatin's use. A CD44+ subpopulation was isolated from human androgen-independent PC3 PCa cells by using human CD44-PE antibody. IC50 values were determined by MTT test. RT-qPCR, Western blot analyses and image-based cytometer were used to investigate apoptosis, cell cycle and their underlying molecular mechanisms. Cell migration was evaluated by wound healing test. The combination of the IC50 doses of apigenin (15µM) and cisplatin (7.5µM) for 48h significantly enhanced cisplatin's cytotoxic and apoptotic effects through downregulation of Bcl-2, sharpin and survivin; and upregulation of caspase-8, Apaf-1 and p53 mRNA expression. The combined therapy suppressed the phosphorylation of p-PI3K and p-Akt, inhibited the protein expression of NF-κB, and downregulated the cell cycle by upregulating p21, as well as cyclin dependent kinases CDK-2, -4, and -6. Apigenin significantly increased the inhibitory effects of cisplatin on cell migration via downregulation of Snail expression. In conclusion, our study showed the possible therapeutic approach of using apigenin to potentially increase the effects of cisplatin by targeting CSCs subset in prostate cancer.

Apigenin inhibited hypoxia induced stem cell marker expression in a head and neck squamous cell carcinoma cell line.

OBJECTIVE: Cancer stem cells contribute to tumor recurrence, and a hypoxic environment is critical for maintaining cancer stem cells. Apigenin is a natural product with anticancer activity. However, the effect of apigenin on cancer stem cells remains unclear. Our aim was to investigate the effect of apigenin on cancer stem cell marker expression in head and neck squamous cell carcinoma cells under hypoxia. DESIGN: We used three head and neck squamous cell carcinoma cell lines; HN-8, HN-30, and HSC-3. The mRNA expression of cancer stem cell markers was determined by semiquantitative RT-PCR and Real-time PCR. The cytotoxic effect of apigenin was determined by MTT colorimetric assay. Flow cytometry was used to reveal the number of cells expressing cancer stem cell surface markers. RESULTS: HN-30 cells, a cancer cell line from the pharynx, showed the greatest response to hypoxia by increasing their expression of CD44, CD105, NANOG, OCT-4, REX-1, and VEGF. Apigenin significantly decreased HN-30 cell viability in dose- and time-dependent manners. In addition, 40µM apigenin significantly down-regulated the mRNA expression of CD44, NANOG, and CD105. Consistent with these results, the hypoxia-induced increase in CD44+ cells, CD105+ cells, and STRO-1+ cells was significantly abolished by apigenin. CONCLUSION: Apigenin suppresses cancer stem cell marker expression and the number of cells expressing cell surface markers under hypoxia.

Effects of flavopiridol on critical regulation pathways of CD133high/CD44high lung cancer stem cells.

BACKGROUND: Flavopiridol a semisynthetic flavone that inhibits cyclin-dependent kinases (CDKs) and has growth-inhibitory activity and induces a blockade of cell-cycle progression at G1-phase and apoptosis in numerous human tumor cell lines and is currently under investigation in phase II clinical trials. Cancer stem cells (CSCs) are comprised of subpopulation of cells in tumors that have been proposed to be responsible for recurrence and resistance to chemotherapy. The aim of the present study was to investigate the effects of flavopiridol in cancer stem cell cytoskeleton, cell adhesion, and epithelial to mesenchymal transition in CSCs. METHODS: The cells were treated with flavopiridol to determine the inhibitory effect. Cell viability and proliferation were determined by using the WST-1 assay. Caspase activity and immunofluorescence analyses were performed for the evaluation of apoptosis, cell cytoskeleton, and epithelial-mesenchymal transition (EMT) markers. The effects of flavopiridol on the cell cycle were also evaluated. Flow cytometric analysis was used to detect the percentages of CSCs subpopulation. We analyzed the gene expression patterns to predict cell cycle and cell cytoskeleton in CSCs by RT-PCR. RESULTS: Flavopiridol-induced cytotoxicity and apoptosis at the IC50 dose, resulting in a significant increase expression of caspases activity. Cell cycle analyses revealed that flavopiridol induces G1 phase cell cycle arrest. Flavopiridol significantly decreased the mRNA expressions of the genes that regulate the cell cytoskeleton and cell cycle components and cell motility in CSCs. CONCLUSION: Our results suggest that Flavopiridol has activity against lung CSCs and may be effective chemotherapeutic molecule for lung cancer treatment.

Hyaluronic Acid in Inflammation and Tissue Regeneration.

Hyaluronic acid (HA), the main component of extracellular matrix, is considered one of the key players in the tissue regeneration process. It has been proven to modulate via specific HA receptors, inflammation, cellular migration, and angiogenesis, which are the main phases of wound healing. Studies have revealed that most HA properties depend on its molecular size. High molecular weight HA displays anti-inflammatory and immunosuppressive properties, whereas low molecular weight HA is a potent proinflammatory molecule. In this review, the authors summarize the role of HA polymers of different molecular weight in tissue regeneration and provide a short overview of main cellular receptors involved in HA signaling. In addition, the role of HA in 2 major steps of wound healing is examined: inflammation and the angiogenesis process. Finally, the antioxidative properties of HA are discussed and its possible clinical implication presented.

Hyaluronan/Hyaladherins - a Promising Axis for Targeted Drug Delivery in Cancer.

BACKGROUND: Hyaluronan (HA), a glycosaminoglycan, is a key extracellular matrix (ECM) component, and has been established to contribute to fibrotic, angiogenic, inflammatory as well as processes supporting cancer development. The changes in HA deposition in different tumors have been widely studied. Indeed, a multitude of reports demonstrate that HA expression is increased in different neoplasmatic tissues including lung, colon, prostate and breast cancer. The aims of this paper are to critically and in depth discuss aspects of HA metabolism in cancer and recent developments of its utilization in cancer therapy. METHODS: Up to date research and online content are reviewed. RESULTS: The cellular roles of HA are perpetrated through molecular interactions with HA-binding proteins, called hyaladherins, including CD44 receptor as well as receptor for hyaluronan-mediated motility (RHAMM). HA binding can be followed by receptor-mediated endocytosis. Importantly, hyaladherins show an altered expression in tumor tissues. Indeed, post-translational alterations in CD44 structure have been suggested to regulate the equilibrium between the "inactive" low affinity state and the "active" high affinity state of the HA binding capacity. In this concept HA fragments can be utilized as specific targeting ligands for efficient and safe drug delivery in cancer. CONCLUSION: HA-drug bioconjugates and nanoparticles have emerged as a promising platform for drug delivery during cancer treatment as demonstrated in various pre-clinical studies. Recent developments from clinical trials indicate that the utilization of specific HA-drug bioconjugates might be approved for the medical practice in the nearest future.

CD44(high) /ALDH1(high) head and neck squamous cell carcinoma cells exhibit mesenchymal characteristics and GSK3ß-dependent cancer stem cell properties.

BACKGROUND: CD44 and aldehyde dehydrogenase 1 (ALDH1) have been shown to be useful markers for identification of cancer stem cells (CSCs). We previously reported that glycogen synthase kinase 3ß (GSK3ß) is involved in regulation of the self-renewal ability of head and neck squamous cell carcinoma (HNSCC) CSCs. The purpose of the present study was to clarify the role of GSK3ß in CD44(high) /ALDH1(high) HNSCC cells. METHODS: Cells with greater expression of CD44 and higher ALDH1 enzymatic activity were FACS sorted from the OM-1 HNSCC cell line. The self-renewal ability of CD44(high) /ALDH1(high) cells was then examined using a tumor sphere formation assay. mRNA expressions of the stem cell markers Sox2, Oct4, and Nanog, as well as GSK3ß were evaluated by real-time RT-PCR. RESULTS: CD44(high) /ALDH1(high) cells exhibited higher tumor sphere forming ability and increased expression of stem cell markers as compared with CD44(high) /ALDH1(low) cells. Interestingly, spindle-shaped cells positive for vimentin were found in the CD44(high) /ALDH1(high) but not the CD44(high) /ALDH1(low) cell population. In addition, the ALDH1 activity and sphere forming ability of CD44(high) /ALDH1(high) cells was significantly inhibited by GSK3ß knockdown. On the other hand, CD44(high) /ALDH1(low) cells exhibited high epidermal growth factor receptor (EGFR) expression and increased cell growth. CONCLUSIONS: Our results show that GSK3ß plays a major role in maintenance of stemness of CD44(high) /ALDH1(high) HNSCC cells. Additionally, they indicate a close relationship between CSC and mesenchymal characteristics in HNSCC.

Effects of peritumoral nanoconjugated cisplatin on laryngeal cancer stem cells.

OBJECTIVES/HYPOTHESIS: To evaluate the efficacy of peritumoral hyaluronic acid (HA)-cisplatin therapy in a murine model of laryngeal squamous cell carcinoma and to evaluate its effect on cancer stem cells (CSCs). STUDY DESIGN: An orthotopic murine study utilizing University of Michigan squamous cell carcinoma-12 (UMSCC-12) laryngeal cancer cells was conducted in randomized controlled fashion with three treatment arms: saline, systemic cisplatin, and peritumoral HA-cisplatin. METHODS: UMSCC-12 laryngeal cancer cells were inoculated into the buccal mucosa of athymic nude mice followed by weekly treatment with saline, systemic cisplatin, or peritumoral HA-cisplatin for 3 weeks. Tumor response and animal weight was monitored and change in CD44 proportion was analyzed ex vivo. RESULTS: HA-cisplatin demonstrated superior antitumor efficacy and greater reduction in CD44 positivity on ex vivo analysis. CONCLUSIONS: Peritumoral nanoconjugated HA-cisplatin provides superior antitumor efficacy compared to standard cisplatin therapy in an in vivo laryngeal cancer model. There was also selective targeting of CD44+ cancer cells with HA-cisplatin. This therapeutic strategy could represent the first selective laryngeal CSC-targeted therapy. Further preclinical investigation is warranted to evaluate its role for locally advanced head and neck cancer treatment. LEVEL OF EVIDENCE: NA Laryngoscope, 126:E184-E190, 2016.

Identification, design and synthesis of tubulin-derived peptides as novel hyaluronan mimetic ligands for the receptor for hyaluronan-mediated motility (RHAMM/HMMR).

Fragments of the extracellular matrix component hyaluronan (HA) promote tissue inflammation, fibrosis and tumor progression. HA fragments act through HA receptors including CD44, LYVE1, TLR2, 4 and the receptor for hyaluronan mediated motility (RHAMM/HMMR). RHAMM is a multifunctional protein with both intracellular and extracellular roles in cell motility and proliferation. Extracellular RHAMM binds directly to HA fragments while intracellular RHAMM binds directly to ERK1 and tubulin. Both HA and regions of tubulin (s-tubulin) are anionic and bind to basic amino acid-rich regions in partner proteins, such as in HA and tubulin binding regions of RHAMM. We used this as a rationale for developing bioinformatics and SPR (surface plasmon resonance) based screening to identify high affinity anionic RHAMM peptide ligands. A library of 12-mer peptides was prepared based on the carboxyl terminal tail sequence of s-tubulin isoforms and assayed for their ability to bind to the HA/tubulin binding region of recombinant RHAMM using SPR. This approach resulted in the isolation of three 12-mer peptides with nanomolar affinity for RHAMM. These peptides bound selectively to RHAMM but not to CD44 or TLR2,4 and blocked RHAMM:HA interactions. Furthermore, fluorescein-peptide uptake by PC3MLN4 prostate cancer cells was blocked by RHAMM mAb but not by CD44 mAb. These peptides also reduced the ability of prostate cancer cells to degrade collagen type I. The selectivity of these novel HA peptide mimics for RHAMM suggest their potential for development as HA mimetic imaging and therapeutic agents for HA-promoted disease.

Innovative therapy of ovarian cancer based on overexpression of CD44 receptor.

Ovarian carcinoma constitutes the main cause of cancer-related death among women. The curability rates remain low despite rapid advances in medicine. Thus, the search for new and improved methods continues, with CD44-targeting as one of them. CD44 is a cell-surface glycoprotein, which binds to its ligand--hyaluronic acid (HA)--and regulates crucial processes such as cell differentiation, proliferation and migration. Overexpression of CD44, observed in many ovarian cancer cells, is used in creating carriers for selective delivery of various drugs (paclitaxel, doxorubicin, camptothecin or cisplatin) to cancer cells. In this article, we summarized the current state of knowledge regarding CD44-targeting as a new and more efficient way of ovarian cancer treatment, with high potential and promising therapeutic perspectives.