Curcumin and its Analogs and Carriers: Potential Therapeutic Strategies for Human Osteosarcoma

Dietary factors and their influence on immunotherapy strategies in oncology: a comprehensive review

Immunotherapy is emerging as a promising avenue in oncology, gaining increasing importance and offering substantial advantages when compared to chemotherapy or radiotherapy. However, in the context of immunotherapy, there is the potential for the immune system to either support or hinder the administered treatment. This review encompasses recent and pivotal studies that assess the influence of dietary elements, including vitamins, fatty acids, nutrients, small dietary molecules, dietary patterns, and caloric restriction, on the ability to modulate immune responses. Furthermore, the article underscores how these dietary factors have the potential to modify and enhance the effectiveness of anticancer immunotherapy. It emphasizes the necessity for additional research to comprehend the underlying mechanisms for optimizing the efficacy of anticancer therapy and defining dietary strategies that may reduce cancer-related morbidity and mortality. Persistent investigation in this field holds significant promise for improving cancer treatment outcomes and maximizing the benefits of immunotherapy.

Curcumin-Piperlongumine Hybrid Molecule Increases Cell Cycle Arrest and Apoptosis in Lung Cancer through JNK/c-Jun Signaling Pathway

The instability of curcumin's structure and the toxic side effects of piperlongumine have limited their potential applications in cancer treatment. To overcome these challenges, we designed and synthesized a novel curcumin-piperlongumine hybrid molecule, 3-[(E)-4-hydroxy-3-methoxybenzylidene]-1-[(E)-3-(3,4,5-trimethoxyphenyl)acryloyl]piperidin-2-one (CP), using a molecular hybridization strategy. CP exhibited enhanced structural stability and safety compared with its parent compounds. Through in vitro and in vivo biological activity screenings, CP effectively inhibited cell proliferation, caused cell cycle arrest in the G2/M phase, and induced apoptosis. Mechanistically, CP-induced apoptosis was partially mediated by cell cycle arrest. Furthermore, we discovered that CP induces cell cycle arrest and apoptosis through the regulation of JNK signaling. These findings highlight the potential of CP as a promising therapeutic agent for lung cancer treatment.

Morin inhibits osteosarcoma migration and invasion by suppressing urokinase plasminogen activator through a signal transducer and an activator of transcription 3

Osteosarcoma, the most common primary bone cancer that affects adolescents worldwide, has the early metastatic potential to be responsible for high mortality rates. Morin has a multipurpose role in numerous cancers, whereas little is known about its role in osteosarcoma migration and invasion. Therefore, we hypothesized that morin suppresses the invasive activities and the migratory potential of human osteosarcoma cells. Our results showed that morin reduced migration and invasion capabilities in human osteosarcoma U2OS and HOS cells. Moreover, morin inhibited the urokinase plasminogen activator (uPA) expression through a signal transducer and an activator of transcription-3 (STAT3) phosphorylation. After STAT3 overexpression, the decrease of the migratory potential and uPA expression caused by 100 μM of morin in U2OS cells was countered, indicating that STAT3 contributes to the antimetastatic property of morin in human osteosarcoma cells by reducing uPA. In conclusion, morin may be a potential candidate for the antimetastatic treatment of human osteosarcoma.

Curcumin Analog L48H37 Induces Apoptosis in Human Oral Cancer Cells by Activating Caspase Cascades and Downregulating the Inhibitor of Apoptosis Proteins through JNK/p38 Signaling

L48H37 is a synthetic curcumin analog that has anticancer potentials. Here, we further explored the anticancer effect of L48H37 on oral cancer cells and its mechanistic acts. Cell cycle distribution was assessed using flow cytometric analysis. Apoptosis was elucidated by staining with PI/Annexin V and activation of the caspase cascade. Cellular signaling was explored using apoptotic protein profiling, Western blotting, and specific inhibitors. Our findings showed that L48H37 significantly reduced the cell viability of SCC-9 and HSC-3 cells, resulting in sub-G1 phase accumulation and increased apoptotic cells. Apoptotic protein profiling revealed that L48H37 increased cleaved caspase-3, and downregulated cellular inhibitor of apoptosis protein 1 (cIAP1) and X-linked inhibitor of apoptosis protein (XIAP) in SCC-9 cells, and the downregulated cIAP1 and XIAP in both oral cancer cells were also demonstrated by Western blotting. Meanwhile, L48H37 triggered the activation of caspases and mitogen-activated protein kinases (MAPKs). The involvement of c-Jun N-terminal kinase (JNK) and p38 MAPK (p38) in the L48H37-triggered apoptotic cascade in oral cancer cells was also elucidated by specific inhibitors. Collectively, these findings indicate that L48H37 has potent anticancer activity against oral cancer cells, which may be attributed to JNK/p38-mediated caspase activation and the resulting apoptosis. This suggests a potential benefit for L48H37 for the treatment of oral cancer.

HO-3867, a curcumin analog, elicits cell apoptosis and p38-mediated caspase activation in hepatocellular carcinoma

HO-3867, a synthetic curcumin analog, has displayed various tumor-suppressive characteristics and improved bioabsorption over its parent compound. However, its influences on the development of hepatocellular carcinoma (HCC) are poorly defined. To address this, we tested the anticarcinogenic impact of HO-3867 and investigated the underlying mechanisms in fighting liver cancer. Our result demonstrated that HO-3867 reduced the viability of HCC cells, accompanied by promotion of cell cycle arrest at the sub-G1 stage and apoptotic responses. Furthermore, a distinctive profile of apoptosis associated proteins, encompassing elevated heme oxygenase-1 (HO-1) level and caspase activation, was detected in HO-3867-stimulated HCC cells. In addition, such HO-3867-mediated elevation in caspase activation was dampened by pharmacological suppression of p38 activities. Taken together, our findings unveiled that HO-3867 triggered cell cycle arrest and apoptotic events in liver cancer, involving a p38-mediated activation of caspase cascades. These data highlighted a usefulness of curcumin or its analogs on the management of hepatocarcinogenesis.

The current status and future of PD-L1 in liver cancer

The application of immunotherapy in tumor, especially immune checkpoint inhibitors (ICIs), has played an important role in the treatment of advanced unresectable liver cancer. However, the efficacy of ICIs varies greatly among different patients, which has aroused people's attention to the regulatory mechanism of programmed death ligand-1 (PD-L1) in the immune escape of liver cancer. PD-L1 is regulated by multiple levels and signaling pathways in hepatocellular carcinoma (HCC), including gene variation, epigenetic inheritance, transcriptional regulation, post-transcriptional regulation, and post-translational modification. More studies have also found that the high expression of PD-L1 may be the main factor affecting the immunotherapy of liver cancer. However, what is the difference of PD-L1 expressed by different types of cells in the microenvironment of HCC, and which type of cells expressed PD-L1 determines the effect of tumor immunotherapy remains unclear. Therefore, clarifying the regulatory mechanism of PD-L1 in liver cancer can provide more basis for liver cancer immunotherapy and combined immune treatment strategy. In addition to its well-known role in immune regulation, PD-L1 also plays a role in regulating cancer cell proliferation and promoting drug resistance of tumor cells, which will be reviewed in this paper. In addition, we also summarized the natural products and drugs that regulated the expression of PD-L1 in HCC.

Synthesis of modified bile acids via palladium-catalyzed C(sp3)-H (hetero)arylation

A Pd(II)-catalyzed strategy for the diastereo- and regioselective (hetero)arylation of unactivated C(sp3)-H bonds in bile acids is accomplished with aryl and heteroaryl iodides under solvent-free conditions using the 8-aminoquinoline auxiliary as a directing group. This methodology demonstrated excellent functional group tolerance with respect to aryl/heteroaryl iodides on O-protected N-(quinolin-8-yl)cholyl/deoxycholyl amides to afford β-C(sp3)-H (hetero)arylated products in good-to-excellent yields. Moreover, the 8-aminoquinoline (AQ) auxiliary can easily be removed to obtain modified bile acids.

NEK6 Promotes the Progression of Osteosarcoma Through Activating STAT3 Signaling Pathway by Down-Regulation of miR-26a-5p

Background

Osteosarcoma is a malignant tumor originating from the skeletal system. There is no effective treatment other than surgery and chemotherapy, which seriously endangers the health of children and adolescents. NEK6 is a novel discovered Serine/Threonine protein kinase that can regulate cell cycle and activate several oncogenic pathways.

Methods

NEK6 expression in pan-cancer including sarcoma was evaluated using analysis tools of TIMER, UALCNA and GEPIA with TCGA database, and its association with overall survival in patients with sarcoma was also analyzed. TargetScan, tarbase, microT-CDS and Starbase online software were used to predict NEK6-targeted miRNAs, including miR-26a-5p. Tumor tissues from patients with osteosarcoma were collected for NEK6 and miRNA detection using RT-qPCR. NEK6 down-regulated by siRNAs or miR-26a-5p in osteosarcoma cells was detected by RT-qPCR, Western blot and Immunofluorescence staining assays. Effects of NEK6 knockdown on proliferation, migration, invasion and apoptosis of osteosarcoma cells were detected by CCK-8, wound healing, transwell and flow cytometry, respectively. The expressions of STAT3, metastasis and apoptosis-related genes were detected by Western blot.

Results

High expression of NEK6 and low expression of miR-26a-5p were lowly expressed in osteosarcoma and they were negative correlation. NEK6 has been confirmed as a direct target for miR-26a-5p. In addition, NEK6 down-regulated by siRNAs or miR-26a-5p led to inhibition of cell proliferation, migration and invasion while promoting cell apoptosis. The levels of phosphorylated STAT3 and metastasis genes (MMP-2, MMP-9) were inhibited, while apoptotic gene Bax was promoted and Bcl2 was inhibited by miR-26a-5p upregulation.

Conclusion

NEK6 can promote osteosarcoma progression via activating STAT3 signaling pathway, which is inhibited by miR-26a-5p, suggesting that NEK6 is a potential oncogene and miR-26a-5p is a suppressor of osteosarcoma. The strategy of inhibiting of NEK6 by miR-26a-5p may be an effective approach for osteosarcoma therapy.

Apoptotic effect and cell arrest of deoxyshikonin in human osteosarcoma cells through the p38 pathway

Osteosarcoma is the most common primary bone cancer that affects adolescents with early metastatic potential and drastically reduces their long-term survival rate if pulmonary metastases are detected at diagnosis. The natural naphthoquinol compound deoxyshikonin exhibits anticancer properties, so we hypothesized that it has an apoptotic effect on osteosarcoma U2OS and HOS cells and studied its mechanisms. After deoxyshikonin treatment, dose-dependent decreases in cell viability, induction of cell apoptosis and arrest in the sub-G1 phase of U2OS and HOS cells were observed. The increases in cleaved caspase 3 expression and the decreases in X-chromosome-linked IAP (XIAP) and cellular inhibitors of apoptosis 1 (cIAP-1) expressions after deoxyshikonin treatment in the human apoptosis array were identified in HOS cells, and dose-dependent expression changes of IAPs and cleaved caspase 3, 8 and 9 were verified by Western blotting in U2OS and HOS cells. Phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2, c-Jun N-terminal kinases (JNK)1/2 and p38 expressions in U2OS and HOS cells was also increased by deoxyshikonin in a dose-dependent manner. Subsequently, cotreatment with inhibitors of ERK (U0126), JNK (JNK-IN-8) and p38 (SB203580) was performed to show that p38 signalling is responsible for deoxyshikonin-induced apoptosis in U2OS and HOS cells, but not via the ERK and JNK pathways. These discoveries demonstrate that deoxyshikonin may be a possible chemotherapeutic candidate to induce cell arrest and apoptosis by activating extrinsic and intrinsic pathways through p38 for human osteosarcoma.