Natural Compound Allicin Containing Thiosulfinate Moieties as Transmembrane Protein 16A (TMEM16A) Ion Channel Inhibitor for Food Adjuvant Therapy of Lung Cancer.

Cancer is one of the most serious malignant diseases, and chemotherapy is cancer's main clinical treatment method. However, chemotherapy inevitably produces drug resistance, and side effects accompany them. Adjuvant therapy is an effective way to enhance chemotherapeutic drug sensitivity and reduce side effects. This study found allicin, garlic's active ingredient, is an inhibitor of transmembrane protein 16A (TMEM16A), a novel drug target of lung adenocarcinoma. Allicin concentration-dependently inhibited TMEM16A currents with an IC50 of 24.35 ± 4.14 µM. Allicin thiosulfinate moieties bound with R535A/E624A/E633A residues of TMEM16A blocked the ion transport function and downregulated TMEM16A protein expression affecting the mitogen-activated protein kinase signal transduction. Then, allicin reduced the viability and migration of LA795 cells, and induced cell apoptosis. Moreover, multitarget combination administration results indicated that the therapeutic effect of 3.56 mg/kg allicin and 3 mg/kg cisplatin combined administration was superior to the superposition of the two drugs alone, demonstrating that the anticancer effects of allicin and cisplatin were synergistic. In addition, low-concentration combined administration also avoided the side effects of cisplatin in mice. Based on the good tumor suppressor effect and high biosafety of allicin and cisplatin combination in vivo, allicin can be used for food adjuvant therapy of cisplatin chemotherapy.

Self-healing pectin/cellulose hydrogel loaded with limonin as TMEM16A inhibitor for lung adenocarcinoma treatment.

Lung cancer as one of the highest incident malignant tumors did not receive satisfactory chemotherapy due to lack of specific drug targets and targeted drugs. This study screened a new effective lung tumor inhibitor limonin from herbal medicine, which inhibited proliferation and promoted apoptosis of lung adenocarcinoma cells by targeting specific high expressed TMEM16A ion channel. Moreover, a novel biodegradable self-healing hydrogel was prepared from acylhydrazide functionalized carboxymethyl cellulose (CMC-AH) and oxidized pectin (pec-CHO) to reduce the side effects of the limonin to the body. The hydrogels showed fast gelation, good biocompatibility and sustained limonin release property. The limonin-loaded hydrogel significantly inhibited the growth of lung adenocarcinoma in xenografts mice because the limonin inhibited the proliferation, migration and promoted apoptosis of LA795 cells, and eliminated the acute toxicity through sustained release from the hydrogel. Combined the antitumor performance of the limonin and sustained release of pec-CHO/CMC-AH hydrogel, this limonin/hydrogel system achieved satisfactory antitumor effect and eliminated side effects in vivo. Therefore, this system has great potential application for enhanced lung adenocarcinoma therapy.

Caffeic Acid, an Active Ingredient in Coffee, Combines with DOX for Multitarget Combination Therapy of Lung Cancer.

Adjuvant diet therapy is an important means of comprehensive treatment of cancer. It is recognized by patients for its high safety, painlessness, and ease to operate. However, the development of adjuvant dietary therapy is limited by unclear targets and unclear anticancer mechanisms. In this work, caffeic acid was found as an inhibitor of TMEM16A with an IC50 of 29.47 ± 3.19 µM by fluorescence quenching and whole-cell patch-clamp experiments. Caffeic acid regulated the proliferation, migration, and apoptosis of lung cancer cells targeting TMEM16A, which was detected by CCK-8, colony formation, wound healing, and Annexin V assays. In addition, molecular docking combined with site-directed mutagenesis confirmed that the binding sites of caffeic acid to TMEM16A were D439, E448, and R753. Western blot results indicated that caffeic acid regulated the growth of lung cancer through the MAPK pathway. In vitro experiments showed that the inhibitory effect of caffeic acid combined with hydroxydaunorubicin (DOX) on lung cancer cell growth was better than a double concentration of any single dose. In vivo pharmacokinetic experiments and tumor xenograft experiments indicated that the combination of 5.4 mg/kg caffeic acid and 4.1 mg/kg DOX achieved 85.6% tumor suppression rate and offset the side effects. Therefore, caffeic acid is a safe and efficient antitumor active ingredient of food that can enhance the antitumor effect of DOX.