Manlin Cao

The High and Low Molecular Weight Forms of Hyaluronan Have Distinct Effects on CD44 Clustering

Background: The feature of CD44 binding with native high molecular weight hyaluronan (nHA) and hyaluronan oligosaccharides (oHA) is different. Results: nHA induces but oHA reduces CD44 clustering. Conclusion: nHA and oHA have distinct effects on CD44 clustering. Significance: The study provides direct evidence for the different characteristics of CD44 binding with nHA and oHA in vivo. CD44 is a major cell surface receptor for the glycosaminoglycan hyaluronan (HA). Native high molecular weight hyaluronan (nHA) and oligosaccharides of hyaluronan (oHA) provoke distinct biological effects upon binding to CD44. Despite the importance of such interactions, however, the feature of binding with CD44 at the cell surface and the molecular basis for functional distinction between different sizes of HA is still unclear. In this study we investigated the effects of high and low molecular weight hyaluronan on CD44 clustering. For the first time, we provided direct evidence for a strong relationship between HA size and CD44 clustering in vivo. In CD44-transfected COS-7 cells, we showed that exogenous nHA stimulated CD44 clustering, which was disrupted by oHA. Moreover, naturally expressed CD44 was distributed into clusters due to abundantly expressed nHA in HK-2 cells (human renal proximal tubule cells) and BT549 cells (human breast cancer cell line) without exogenous stimulation. Our results suggest that native HA binding to CD44 selectively induces CD44 clustering, which could be inhibited by oHA. Finally, we demonstrated that HA regulates cell adhesion in a manner specifically dependent on its size. oHA promoted cell adhesion while nHA showed no effects. Our results might elucidate a molecular- and/or cellular-based mechanism for the diverse biological activities of nHA and oHA.

A novel role of low molecular weight hyaluronan in breast cancer metastasis

Low molecular weight hyaluronan (LMW‐HA), a degradation fragment of the extracellular matrix component hyaluronan (HA), has been proven to play a crucial role in cancer progression. However, no systematic clinical study of breast cancer has been performed to correlate LMW‐HA levels with metastasis. In the present study, we analyzed 176 serum specimens and found for the first time that the serum LMW‐HA (but not total HA) level significantly correlated with lymph node metastasis, suggesting that serum LMW‐HA represents a better prognostic indicator of breast cancer progression than HA. Similarly, we found that breast cancer cell lines displaying higher invasive potential had a higher LMW‐HA concentration than less‐invasive cell lines. This higher LMW‐HA level was accompanied by the overexpression of hyaluronan synthase (HAS2) and hyaluronidase (both HYAL1 and HYAL2). Of great importance, decreasing LMW‐HA production significantly inhibited breast cancer cell migration and invasion. Overall, our results suggest that during cancer progression, cancer cells may actively remodel their microenvironment via an autocrine/paracrine‐like process, resulting in elevated LMW‐HA levels, which in turn may facilitate cancer progression by promoting the migration and invasion of cancer cells. Therefore, cancer‐associated LMW‐HA may be a more promising molecular biomarker than total HA for detecting metastasis and may have further applications in breast cancer treatment.—Wu, M., Cao, M., He, Y., Liu, Y., Yang, C., Du, Y., Wang, W., Gao, F. A novel role of low molecular weight hyaluronan in breast cancer metastasis. FASEB J. 29, 1290‐1298 (2015). www.fasebj.org

Comparative study of microRNA profiling in keloid fibroblast and annotation of differential expressed microRNAs

Keloids are tumor-like skin scars that grow as a result of the aberrant healing of skin injuries, with no effective treatment. The molecular mechanism underlying keloid pathogenesis is still largely unknown. In this study, we compared microRNA (miRNA) expression profiles between keloid-derived fibroblasts and normal fibroblasts (including fetal and adult dermal fibroblasts) by miRNA microarray analysis. We found that the miRNA profiles in keloid-derived fibroblasts are different with those in normal fibroblasts. Nine miRNAs were differentially expressed, six of which were significantly up-regulated in keloid fibroblasts (KFs), including miR-152, miR-23b-3p, miR-31-5p, miR-320c, miR-30a-5p, and hsv1-miR-H7, and three of which were significantly down-regulated, including miR-4328, miR-145-5p, and miR-143-3p. Functional annotations of differentially expressed miRNA targets revealed that they were enriched in several signaling pathways important for scar wound healing. In conclusion, we demonstrate that the miRNA expression profile is altered in KFs compared with in fetal and adult dermal fibroblasts, and the expression profile may provide a useful clue for exploring the pathogenesis of keloids. miRNAs might partially contribute to the etiology of keloids by affecting several signaling pathways relevant to scar wound healing.

Carpal Tunnel Syndrome Assessment with Ultrasonography: Value of Inlet-to-Outlet Median Nerve Area Ratio in Patients versus Healthy Volunteers

Objective To evaluate the diagnostic value of the Inlet-to-outlet median nerve area ratio (IOR) in patients with clinically and electrophysiologically confirmed carpal tunnel syndrome (CTS). Methods Forty-six wrists in 46 consecutive patients with clinical and electrodiagnostic evidence of CTS and forty-four wrists in 44 healthy volunteers were examined with ultrasonography. The cross-sectional area (CSA) of the median nerve was measured at the carpal tunnel inlet (the level of scaphoid-pisiform) and outlet (the level of the hook of the hamate), and the IOR was calculated for each wrist. Ultrasonography and electrodiagnostic tests were performed under blinded conditions. Electrodiagnostic testing combined with clinical symptoms were considered to be the gold standard test. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic value between the inlet CSA and IOR. Results The study population included 16 men and 30 women (mean age, 45.3 years; range, 18–83 years). The control population included 18 men and 26 women (mean age, 50.4 years; range, 18–79 years). The mean inlet CSA was 8.7 mm2 in healthy controls and 14.6mm2 in CTS group (P<0.001). The mean IOR in healthy volunteers (1.0) was smaller than that in patients (1.6, P<0.001). Receiver operating characteristic analysis revealed a diagnostic advantage to using the IOR rather than the inlet CSA (P<0.01). An IOR cutoff value of ≥ 1.3 would yield 93% specificity and 91% sensitivity in the diagnosis of CTS. Conclusion The IOR of median nerve area promises to be an effective means in the diagnosis of CTS. A large-scale, randomized controlled trial is required to determine how and when this parameter will be used.

Expression and quantification of LYVE-1 in human colorectal cancer

The recent discovery of a new hyaluronan (HA) receptor, LYVE-1 (lymphatic vessel endothelial HA receptor), has been received with great interest regarding its specific expression in the lymphatic system. The process of lymphangiogenesis or the formation of new lymphatics in tumours is important because it serves as a major route for cancer metastasis. Therefore, methods to quantify lymphangiogenesis by measuring LYVE-1 have been studied extensively in searching for its possible role in cancer diagnosis, prognosis and even targeted treatment of lymphatic tumour metastasis. Here we report a quantitation study on lymphangiogenesis by either quantitative PCR or immunohistochemistry approaches in detecting LYVE-1 expression in human colorectal tumour. Real-time quantitative polymerase chain reaction (RTQ-PCR) was carried out to quantify LYVE-1 levels in colorectal cancer samples. Also, the same specimen was observed for LYVE-1 expression by immunohistochemical stain. By RTQ-PCR amplification, LYVE-1 was highly expressed in colorectal specimens and LYVE-1 signal from non-cancer tissue of normal control was much weaker by conventional RTPCR. Immunohistochemical stain showed that LYVE-1 was significantly expressed in cancer tissues (especially in the margin region of cancer), whereas in non-cancer specimens fewer positive stains were revealed. The results suggested that the LYVE-1 molecule was expressed significantly in colorectal specimens, which may imply a new marker for a malignant situation.

Low-molecular-weight hyaluronan (LMW-HA) accelerates lymph node metastasis of melanoma cells by inducing disruption of lymphatic intercellular adhesion

ABSTRACT Endothelial integrity defects initiate lymphatic metastasis of tumor cells. Low-molecular-weight hyaluronan (LMW-HA) derived from plasma and interstitial fluid was reported to be associated with tumor lymphatic metastasis. In addition, LMW-HA was proved to disrupt lymphatic vessel endothelium integrity, thus promoting lymphatic metastasis of tumor cells. Until now, there are few reports on how LMW-HA modulates lymphatic endothelial cells adhesion junctions and affects cancer cells metastasizing into lymph vessels. The aim of our study is to unravel the novel mechanism of LMW-HA in mediating tumor lymphatic metastasis. Here, we employed a melanoma metastasis model to investigate whether LMW-HA facilitates tumor cells transferring from foci to remote lymph nodes by disrupting the lymphatic endothelial integrity. Our data indicate that LMW-HA significantly induces metastasis of melanoma cells to lymph nodes and accelerates interstitial-lymphatic flow in vivo. Further experiments show that increased migration of melanoma cells across human dermal lymphatic endothelial cell (HDLEC) monolayers is accompanied by impaired lymphatic endothelial barrier function and increased permeability. The mechanism study reveals that VE-cadherin-β-catenin pathway and relevant signals are involved in modulating the interactions between endothelial cells and that a significant inhibition of lymphatic endothelium disruption is observed when antibodies to the LMW-HA receptor (LYVE-1) are present. Thus, our findings demonstrate a disruptive effect of LMW-HA on lymphatic endothelium continuity which leads to a promotion on melanoma lymphatic metastasis and also suggest a cellular signaling mechanism associated with VE-cadherin-mediated lymphatic intercellular junctions.

Chronic lumbar paraspinal compartment syndrome: A CASE REPORT AND REVIEW OF THE LITERATURE

A 25-year-old male weightlifter felt increasing intractable low back pain during training but denied any acute injury. The physical examination, blood parameters, radiographs and MRI were unremarkable. He had been treated non-operatively by various means, with only temporary relief. The pressures in the lumbar paraspinal compartment were abnormally high and he was treated by surgical decompression. This gave rapid relief, he returned to training, and one year later the pain had not recurred.

Increased circulating M2-like monocytes in patients with breast cancer:

M2-like tumor-associated macrophages promote breast tumor growth and survival and may migrate into the peripheral blood. However, the frequency of circulating M2-like monocytes in the peripheral blood of breast cancer patients has not been clarified. The objective of this study was to determine the percentages of circulating M2-like monocytes in patients with breast cancer. Immunofluorescence staining for CD68 and CD163 was performed to detect M2-like macrophages in pathological tissues. Flow cytometry was used to assess the frequencies of circulating CD14+CD163+/CD14+CD204+/CD14+CD163+CD204+ M2-like monocytes in 99 breast cancer patients, 56 patients with benign breast disease, and 60 healthy controls. Receiver operating characteristic curve analysis was used to compare the diagnostic values of circulating M2-like monocytes, carcinoembryonic antigen, and cancer antigen 15-3. The associations among circulating M2-like monocytes and clinical breast cancer parameters were analyzed. The number of CD68+CD163+ M2-like macrophages was significantly higher in breast cancer tissues than in benign tissues. In the peripheral blood, CD14+CD163+/CD14+CD204+/CD14+CD163+CD204+ M2-like monocytes were elevated in breast cancer patients compared with normal controls and patients with benign breast disease. The area under the receiver operating curve for circulating CD14+CD163+CD204+ M2-like monocytes was 0.888 (95% confidence interval: 0.839–0.936), a value higher than those for carcinoembryonic antigen and cancer antigen 15-3. High frequencies of circulating CD14+CD204+ and CD14+CD163+CD204+ M2-like monocytes were associated with tumor–node–metastasis stage, lymph node metastasis, histological differentiation, and estrogen receptor expression. Circulating M2-like monocytes may serve as a diagnostic biomarker in breast cancer and have a potential role in reflecting breast cancer progression.

Inhibition of cell invasion and migration by CEACAM1‑4S in breast cancer

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), a cell-cell adhesion molecule, has been revealed to perform an important role in tumor progression. Although there are a number of studies on CEACAM1 in patients with breast cancer, there is limited information on the roles of CEACAM1 in breast cancer metastasis. The present study aimed to identify whether CEACAM1 is involved in breast cancer development and to investigate the underlying mechanisms. First, the expression of CEACAM1 was observed in patients with breast cancer, and the association between CEACAM1 expression levels and migration and invasion of breast cancer cells was analyzed. As there are 12 isoforms of CEACAM1, of which CEACAM1-4S dominates in the human breast epithelium, subsequent study focused on CEACAM1-4S as a representative of all the isoforms. Results of the present study demonstrated that CEACAM1-4S suppresses breast cancer cell invasion and migration in a manner that is dependent on the balance between matrix metalloproteinase 2/tissue inhibitor of metalloproteinase 2 and E-/N-cadherin expression. In addition, CEACAM1-4S was likely to cause reversal of epithelial-mesenchymal transition of breast cancer cells through repressing Smad2 and signal transducer and phosphorylation of activator of transcription 3. In conclusion, the present study demonstrated that CEACAM1-4S performs an inhibitory role in breast cancer metastasis, and restoring CEACAM1-4S expression may provide a novel strategy for therapy of patients with metastatic breast cancer.

Inducible formation of leading cells driven by CD44 switching gives rise to collective invasion

Collective invasion into adjacent tissue is a hallmark of luminal breast cancer, with about 20% of cases that eventually undergo metastasis. It remained unclear how less aggressive luminal-like breast cancer transit to invasive cancer. Our study revealed that CD44hi cancer cells are the leading subpopulation in collective invading cancer cells, which could efficiently lead the collective invasion of CD44lo/follower cells. CD44hi/leading subpopulation showed specific gene signature of a cohort of hybrid epithelial/mesenchymal state genes and key functional co-regulators of collective invasion, which was distinct from CD44lo/follower cells. However, the CD44hi/leading cells, in partial-EMT state, were readily switching to CD44lo phenotype along with collective movements and vice versa, which is spontaneous and sensitive to tumor microenvironment. The CD44lo-to-CD44hi conversion is accompanied with a shift of CD44s-to-CD44v, but not corresponding to the conversion of non-CSC-to-CSC. Therefore, the CD44hi leader cells are not a stable subpopulation in breast tumors. This plasticity and ability to generate CD44hi carcinoma cells with enhanced invasion-initiating powers might be responsible for the transition from in situ to invasive behavior of luminal-type breast cancer. Significance Now, the mechanisms involved in local invasion and distant metastasis are still unclear. We identified a switch of CD44 that drives leader cell formation during collective invasion in luminal breast cancer. We provided evidence that interconversions between low and high CD44 states occur frequently during collective invasion. Furthermore, these findings demonstrated that the CD44hi/leader cells featuring partial EMT are inducible and attainable in response to tumor microenvironment. The CD44lo cancer cells are plastic that readily shift to CD44hi state, accompanied with shifts of CD44s-to-CD44v, thereby increasing tumorigenic and malignant potential. There are many “non-invasiveness” epithelial/follower cells with reversible invasive potential within an individual tumor, that casting some challenges on molecular targeting therapy.