Background: Breast cancer is the most prevalent cancer among women worldwide. WZ35, an analog of curcumin, has been demonstrated to remarkably improve the pharmacokinetic profiles in vivo compared with curcumin. WZ35 exhibits promising antitumor activity in gastric cancer, HCC, colon cancer. However, antitumor effects of WZ35 in breast cancer and its underlying molecular mechanisms remain unclear. Methods: CCK8, Flow cytometry and transwell assays were used to measure cell proliferation, cell cycle arrest, apoptosis, cell migration and invasion. We constructed xenograft mouse model and lung metastasis model to assess the antitumor activities of WZ35 in vivo. To explore the underlying molecular mechanisms of WZ35, we performed a series of overexpression and knockdown experiments. The cellular oxygen consumption rates (OCRs) was measured to assess mitochondrial dysfunction. Results: We found that treatment of breast cancer cells with WZ35 exerts stronger anti-tumor activities than curcumin both in vitro and in vivo. Mechanistically, our research showed that WZ35 induced reactive oxygen species (ROS) generation and subsequent YAP mediated JNK activation in breast cancer cells. Abrogation of ROS production markedly attenuated WZ35 induced anti-tumor activities as well as YAP and JNK activation. In addition, ROS mediated YAP and JNK activation induced mitochondrial dysfunction in breast cancer cells. Conclusion: Our study showed that novel anti-cancer mechanisms of WZ35 in breast cancer cells and ROS-YAP-JNK pathway might be a potential therapeutic target for the treatment of breast cancer patients.

Objective To investigate the effect of Rapamycin on proliferation and autophagy in human neuroblastoma (NB) cell lines and to elucidate the possible mechanism. Methods NB cells were treated with different concentrations of Rapamycin. Cell counting kit-8 (CCK-8) was used to measure proliferation, and flow cytometry (FCM) was used to analyze the cell cycle. EM was used to observe cell morphological changes. Western blotting (WB) was performed to detect the expression of Beclin-1, LC3-I/II, P62, mammalian target of Rapamycin (mTOR), and p-mTOR. Results Rapamycin inhibited the spread of NB cells in a dose- and time-dependent manner and arrested the cell cycle at the G₀/G₁ phase. EM showed autophagosomes in NB cells treated with Rapamycin. The WB results showed that the expression levels of Beclin-1 and LC3-II/LC3-I were significantly elevated in NB cells treated with Rapamycin, while the expression levels of P62, mTOR, and p-mTOR proteins were significantly reduced compared with the control cells (P<0.05). Conclusion Rapamycin inhibits cell proliferation and induces autophagy in human NB cell lines. The mechanism may be related to suppression of the mTOR signaling pathway.

Curcumin, as a pro-apoptotic agent, is extensively studied to inhibit tumor cell growth of various tumor types. Previous work has demonstrated that curcumin inhibits cancer cell growth by targeting multiple signaling transduction and cellular processes. However, the role of curcumin in regulating cellular bioenergetic processes remains largely unknown. Western blotting and qRT-PCR were performed to analyze the protein and mRNA level of indicated molecules, respectively. RTCA, CCK-8 assay, nude mice xenograft assay, and in vivo bioluminescence imaging were used to visualize the effects of curcmin on gastric cancer cell growth in vitro and in vivo. Seahorse bioenergetics analyzer was used to investigate the alteration of oxygen consumption and aerobic glycolysis rate. Curcumin significantly inhibited gastric tumor cell growth, proliferation and colony formation. We further investigated the role of curcumin in regulating cellular redox homeostasis and demonstrated that curcumin initiated severe cellular apoptosis via disrupting mitochondrial homeostasis, thereby enhancing cellular oxidative stress in gastric cancer cells. Furthermore, curcumin dramatically decreased mtDNA content and DNA polymerase γ (POLG) which contributed to reduced mitochondrial oxygen consumption and aerobic glycolysis. We found that curcumin induced POLG depletion via ROS generation, and POLG knockdown also reduced oxidative phosphorylation (OXPHOS) activity and cellular glycolytic rate which was partially rescued by ROS scavenger NAC, indiating POLG plays an important role in the treatment of gastric cancer. Data in the nude mice model verified that curcumin treatment significantly attenuated tumor growth in vivo. Finally, POLG was up-regulated in human gastric cancer tissues and primary gastric cancer cell growth was notably suppressed due to POLG deficiency. Together, our data suggest a novel mechanism by which curcumin inhibited gastric tumor growth through excessive ROS generation, resulting in depletion of POLG and mtDNA, and the subsequent disruption of cellular bioenergetics.

Gastric cancer is the fourth most common cancer and the second most frequent cause of cancer death worldwide. Chemotherapy is an important treatment. However, traditional chemotherapy drugs have low bioavailability and targeting ability. Therefore, we developed curcumin-encapsulated micelles for the treatment of gastric cancer and investigated their antitumor efficacy and active mechanism. Gastric cancer cells were treated with different concentrations of curcumin micelles. MTS cell proliferation assays, flow cytometry (FCM), real time cellular analysis (RTCA) and nude mice xenografts were used to evaluate the effects of curcumin micelles on gastric cancer cell growth in vitro and in vivo. Western blotting was performed to analyze the protein levels of the indicated molecules. A Seahorse bioenergetics analyzer was used to investigate alterations in oxygen consumption and the aerobic glycolysis rate. Curcumin micelles significantly inhibited proliferation and colony formation and induced apoptosis in gastric tumor cells compared to the control groups. We further investigated the mechanism of curcumin micelles on gastric tumor cells and demonstrated that curcumin micelles acted on mitochondrial proteins, causing changes in mitochondrial function and affecting mitochondrial bioenergetics. Furthermore, curcumin micelles decreased mitochondrial membrane potential, increased reactive oxygen species (ROS) generation and disrupted redox equilibrium. The nude mouse model verified that curcumin micelle treatment significantly attenuated tumor growth in vivo. Curcumin micelles suppress gastric tumor cell growth in vitro and in vivo. The mechanism may be related to increasing ROS generation, disrupting redox equilibrium and affecting mitochondrial bioenergetics.

Hepatocellular carcinoma (HCC) is a common cancer type throughout the world. Due to the high occurrence rate and mortality, liver cancer is one of the leading causes of cancer associated death. With the development of monoclonal antibodies and immunotherapy, the mortality of HCC cancer patients has reduced. However, the recurrence and outcomes of patients remain poor. Therefore, there is an urgent need to develop more effective drugs for HCC therapy. WZ35, a novel curcumin derivative, exhibits potential anti-tumor activity in gastric cancer cells by regulating ROS dependent JNK activation and ER stress. Here, we evaluated the tumor suppressive activity of WZ35 in hepatocellular carcinoma in vitro and in vivo. CCK-8 was used to detect cell viability with or without curcumin or WZ35; cell apoptosis was determined by flow cytometry analysis; GFP-LC3 plasmids were used to investigate the level of autophagy-associated LC3; siRNA transfection was applied to silence endogenous YAP; and western blot was performed to detect the alteration of indicated molecules. Bioinformatics analysis and IHC assay were applied to evaluate the YAP level in normal and liver cancer tissues. In this study, we found that WZ35 effectively suppresses HCC cancer cell growth in vitro and in vivo by promoting cell apoptosis. Importantly, downregulation of YAP contributes to WZ35 caused autophagy inhibition which is different from that of curcumin. We also confirmed that WZ35 is more effective at suppressing HCC cell growth in vivo. Finally, we confirmed that YAP was significantly overexpressed in liver cancer tissues. Collectively, these data indicate that WZ35 could be considered as a promising compound for HCC therapy.

Tumor metastasis is the leading cause of cancer death; due to the progress made in the elucidation of the mechanism of cancer cell metastasis, there is hope for patients with severe stages of cancer. Curcumin, as a novel anti-cancer drug, has been applied in cancer therapy; however, the toxicity of curcumin hinders its application. Herein, we constructed a novel derivative, WZ35, and evaluated its metastatic inhibition properties in vitro and in vivo. CCK-8 assay was performed to evaluate the tumor suppressive activity of WZ35. Cell apoptosis was detected by flow cytometry analysis. Transwell cell migration assay and RTCA were used to detect cell migration in mock and WZ35-treated cells. Western blotting was performed to analyze molecular alteration with different treatments. In this study, we found that curcumin and its derivative WZ35 could dramatically suppress proliferation, invasion, and migration of the hepatocellular HCCLM3, HepG2, and Huh7 cancer cells. Moreover, the cancer cell metastatic markers MMP-2, MMP-9, and N-cadherin were decreased, and E-cadherin was up-regulated. In addition, our data show that WZ35 promotes ROS-dependent JNK activation that is essential for WZ35-caused cell metastasis suppression. Moreover, the NAC and JNK inhibitor SP600125 could dramatically reverse WZ35-caused MMP-2, MMP-9, and N-cadherin reduction and E-cadherin up-regulation. We have also found that WZ35 exhibits powerful anti-metastasis activity of HCCLM3 in vivo. In conclusion, our data indicated that WZ35 could be a candidate for the treatment of metastatic liver cancer patients.