Polydopamine Nanoparticles-Based Photothermal Effect Against Adhesion Formation in a Rat Model of Achilles Tendon Laceration Repair.

Background: Adhesion formation after tendon surgery is a major obstacle to repair of tendon ruptures, and there is still no effective clinical anti-adhesion method. Myofibroblasts expressing α-smooth muscle actin (α-SMA) play a crucial role in adhered fibrous tissue. Heat shock protein (Hsp) 72 can selectively prevent the activation of c-Jun N-terminal kinase (JNK), which mediates the conversion from fibroblasts to myofibroblasts. The purpose of this study was to investigate for the first time whether polydopamine nanoparticles (PDA NPs)-based photothermal effect would attenuate adhesion formation in a rat model of Achilles tendon laceration repair. Materials and Methods: Forty-five adult male Sprague-Dawley rats were randomly assigned to the photothermal group, the control group and the PDA NPs group (n = 15 per group). The primary outcome measure was the adhesion scores at two weeks after surgery according to the grading of Tang et al. The secondary outcomes included the expressions of Hsp 72, JNK, phosphorylated JNK and α-SMA, which were measured by immunohistochemistry or Western blot. Results: The average adhesion score was significantly lower in the photothermal group (4.25 ± 0.21) than that in the control group (5.29 ± 0.12) (p = 0.005) and the PDA NPs group (5.29 ± 0.20) (p = 0.005). Relative to the control group and PDA NPs group, Hsp 72 in the photothermal group was significantly increased whereas α-SMA and p-JNK was significantly decreased, but JNK was not found to be different across the three groups. Conclusion: The photothermal effect produced by PDA NPs could reduce tendon adhesion formation in rats by inhibiting myocyte fibrosis, which may have potential in developing endogenous heating for postsurgical tissue adhesions.

Combined Verapamil-Polydopamine Nanoformulation Inhibits Adhesion Formation in Achilles Tendon Injury Using Rat Model.

Introduction: Topical verapamil has been demonstrated to reduce the fibroproliferative scar. Therefore, it was hypothesized that topical verapamil could reduce adhesion formation after tendon repair. The current study aimed to examine the effects of verapamil-loaded polydopamine nanoparticles (VP-PDA NPs) on the adhesion formation of Achilles tendon laceration and repair in a rat model. Methods: We randomly assigned 72 male Sprague-Dawley rats to the control, the PDA NPs, and the VP-PDA NPs groups (n = 24 per group). The quality of tendon healing was evaluated by the maximal tensile strength four and six weeks after surgery. The degree of tendon adhesion was scored on days 4, 15, 29, and 43 after surgery. The expressions of transforming growth factor-beta 1 (TGF-ß1), vimentin, α-smooth muscle actin (α-SMA), and collagens type I and III were detected through Western blotting or immunohistochemistry at four weeks after surgery. Results: In vitro release tests revealed that 61.3% of verapamil was released from VP-PDA NPs in four weeks. There was a significant increase in average failure to load in the VP-PDA NPs group (89.27 ± 5.09 N) compared with the PDA NPs group (65.52 ± 2.04 N) (p = 0.003) and the control group (74.52 ± 4.24 N) (p = 0.029). Adhesion scores were significantly reduced in the VP-PDA NPs group at six weeks (3.175 ± 0.08) and four weeks (3.35 ± 0.25) compared with the other groups. Moreover, VP-PDA NPs significantly reduced the expression of vimentin, α-SMA, TGF-ß1, and collagens type I and III. Conclusion: These data suggest that VP-PDA NPs reduced adhesion formation and enhanced tendon healing during rat tendon injury. Since topical verapamil has been used in clinics without side effects, VP-PDA NPs would have direct translation implications. However, its anti-adhesive effects on intrasynovial tendon injury must be examined.

Chronic lymphocytic leukemia/small lymphocytic lymphoma complicated with skin Langerhans cell sarcoma: A case report.

BACKGROUND: Langerhans cell sarcoma (LCS) is a rare malignancy with poor prognosis. LCS and chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) can occur in the same diseased tissues, such as lymph nodes or skin. CASE SUMMARY: A 48-year-old female Han Chinese patient was admitted for generalized lymph node enlargement for 6 years and abdominal distension for 1 wk. She was diagnosed with small B-cell lymphoma (stage IV)/CLL (Benet stage B) and received chemotherapy. She started oral ibrutinib in February 2019. She was hospitalized on June 11, 2019, and a 1.5 cm × 1.5 cm dark-red nodule with ulceration scalp lesion was found. Biopsy revealed LCS but without CLL/SLL. She was diagnosed with CLL/SLL (Binet stage C, Rai stage IV) accompanied by secondary histiocytic sarcomas and skin LCS and received cyclophosphamide, doxorubicin, vincristine, dexamethasone, and etoposide but developed severe cytopenia. She ultimately refused treatments and discharged spontaneously. She died on September 12, 2019. The literature review showed that in patients with CLL/SLL, skin lesions of LCS are accompanied by CLL/SLL. This patient was different from the previously reported cases of skin LCS in patients with CLL/SLL. CONCLUSION: In this patient, the skin lesion of LCS showed no concomitant CLL/SLL.

Inhibition of Ubiquitin Specific Protease 1 Sensitizes Colorectal Cancer Cells to DNA-Damaging Chemotherapeutics.

Mutations and altered expression of deubiquitinating enzymes (DUBs) have been found associated with many human diseases including cancers. In this study, Ubiquitin specific protease 1 (USP1) expression was found significantly increased in some colorectal cancers (CRC). The elevated USP1 level was associated with short overall survival of patients and with advanced stages of cancers. In cultured CRC cells, knockdown of USP1 induced growth arrest at G2/M of cell cycle and reduced the expression of anti-apoptotic proteins Bcl-2 and Mcl-1. Its knockdown also led to reduction of DNA-repair related substrates FANCD2 and ID1. Further investigations found that small molecular inhibitor of USP1 ML323 sensitized CRC cells to DNA-targeting chemotherapeutics, including doxorubicin, TOPI/II inhibitors, and PARP inhibitor, but not to 5-Fu. These results indicate that USP1 plays a critical in colorectal cancer cell survival and is a promising target for anti-colorectal cancer chemotherapy. Targeting USP1 may represent an effective strategy to regulate the DNA-repairing system.

Antimalarial drug mefloquine inhibits nuclear factor kappa B signaling and induces apoptosis in colorectal cancer cells.

Nuclear factor kappa B (NF-κB) signaling pathway is activated in many colorectal cancer (CRC) cells and in the tumor microenvironment, which plays a critical role in cancer initiation, development, and response to therapies. In the present study, we found that the widely used antimalarial drug mefloquine was a NF-κB inhibitor that blocked the activation of IκBα kinase, leading to reduction of IκBα degradation, decrease of p65 phosphorylation, and suppressed expression of NF-κB target genes in CRC cells. We also found that mefloquine induced growth arrest and apoptosis of CRC cells harboring phosphorylated p65 in culture and in mice. Furthermore, expression of constitutive active IKKß kinase significantly attenuated the cytotoxic effect of the compound. These results showed that mefloquine could exert antitumor action through inhibiting the NF-κB signaling pathway, and indicated that the antimalarial drug might be repurposed for anti-CRC therapy in the clinic as a single agent or in combination with other anticancer drugs.

α-Actinin-4 is required for amoeboid-type invasiveness of melanoma cells.

α-Actinin-4 (ACTN4), a key regulator of the actin cytoskeleton, is up-regulated in melanoma, though its role in melanoma remains speculative. We have discovered that in WM1158, a highly aggressive melanoma cell line, down-regulation of ACTN4 by shRNA induces a collagen I-dependent amoeboidal-to-mesenchymal transition. Re-expression of low levels of WT ACTN4 but not similar expression levels of ACTN1 successfully restores the amoeboidal morphology and limits collagen I gel compaction. A truncated ACTN4 mutant 1-890, which lacks the C-terminal tail, fails to rescue the amoeboidal morphology and to compact collagen I gel. Interestingly, in three-dimensional collagen I gels, ACTN4 KD cells are more polarized compared with cells in which scrambled shRNA is expressed. Surprisingly, ACTN4 KD cells migrate faster than the ones expressing the scrambled shRNA on a collagen I gel (two-dimensional) although these two cell lines migrate similarly on tissue culture. Most importantly, down-regulation of ACTN4 significantly reduced invasion of WM1158 cells into the three-dimensional collagen I gel, a representative of the dermis. Taken together, these findings suggest that ACTN4 plays an important role in maintaining the amoeboidal morphology of invasive melanoma and thus promoting dissemination through collagen-rich matrices.

[Effects of antisense 6 gene on colon cancer cells].

OBJECTIVE: To investigate the effect of antisense integrin beta6 gene on the growth of colon cancer cells. METHODS: Expressing vector of antisense alphavbeta6 was constructed. Human colon cancer cells of the line HT29 were cultured and divided into 3 groups: Group A, remaining wild type; Group B, transfected with antisense integrin beta6 gene; and Group C, transfected with blank vector. RT-PCR was used to detect the integrin beta6 mRNA expression of in the HT29 cells. The integrinbeta6 protein expression on the surface of the cells was detected by immunohistochemistry and flow cytometry. The binding between the cells and fibronectin was examined. (3)H-labeled thymidine (T) was added into the culture fluid of the cells, and then the radiation amount was detected every 6 days so as to determine the capacity to proliferation of the cells in vitro. Thirty female nude mice were divided into 3 groups to be injected subcutaneously with suspension of HT29 cells of Groups A, B, and C as mentioned above. Six weeks later the size of tumors was measured and part of the tumor nodules were resected 5 weeks after the inoculation to undergo pathological examination. RESULTS: Compared with Groups A and C, no corresponding band at 141 bp was found in Group B by RT-PCR. Flow cytometry showed that the expression level of beta6 protein had was (0.30 +/- 0.051, 30%), significantly lower than those of Groups A and C [(0.80 +/- 0.038, 80%) and (0.85 +/- 0.045, 85%), both P < 0.01]. The binding between the HT29 cells and fibronectin of Group B was significantly degraded after the further addition of anti-beta1 and anti-alphav in comparison of Groups A and C (both P < 0.01). The accumulation values of (3)H-labeled T of Group B 2, 4, and 6 days after addition were all significantly lower than those of Groups A and C (all P < 0.01). The tumors in 9 of the 10 mice injected with the HT29 cells of Group B disappeared and the tumor in the only one mice in Group B was only less than 1 mm(3), significantly smaller then those in Groups A and C (15 mm(3) on average, all P < 0.01). CONCLUSION: Antisense beta6 gene significantly inhibits the mRNA and protein expression of the beta6 gene, and then inhibits the growth and proliferation of colon cancer cells, thus proving that integrin beta6 plays an important role in the regulation of colon cancer cells.