New insights into antiangiogenic therapy resistance in cancer: Mechanisms and therapeutic aspects.

Angiogenesis is a hallmark of cancer and is required for tumor growth and progression. Antiangiogenic therapy has been revolutionarily developing and was approved for the treatment of various types of cancer for nearly two decades, among which bevacizumab and sorafenib continue to be the two most frequently used antiangiogenic drugs. Although antiangiogenic therapy has brought substantial survival benefits to many cancer patients, resistance to antiangiogenic drugs frequently occurs during clinical treatment, leading to poor outcomes and treatment failure. Cumulative evidence has demonstrated that the intricate interplay among tumor cells, bone marrow-derived cells, and local stromal cells critically allows for tumor escape from antiangiogenic therapy. Currently, drug resistance has become the main challenge that hinders the therapeutic efficacies of antiangiogenic therapy. In this review, we describe and summarize the cellular and molecular mechanisms conferring tumor drug resistance to antiangiogenic therapy, which was predominantly associated with redundancy in angiogenic signaling molecules (e.g., VEGFs, GM-CSF, G-CSF, and IL17), alterations in biological processes of tumor cells (e.g., tumor invasiveness and metastasis, stemness, autophagy, metabolic reprogramming, vessel co-option, and vasculogenic mimicry), increased recruitment of bone marrow-derived cells (e.g., myeloid-derived suppressive cells, tumor-associated macrophages, and tumor-associated neutrophils), and changes in the biological functions and features of local stromal cells (e.g., pericytes, cancer-associated fibroblasts, and endothelial cells). We also review potential biomarkers to predict the response to antiangiogenic therapy in cancer patients, which mainly consist of imaging biomarkers, cellular and extracellular proteins, a certain type of bone marrow-derived cells, local stromal cell content (e.g., pericyte coverage) as well as serum or plasma biomarkers (e.g., non-coding RNAs). Finally, we highlight the recent advances in combination strategies with the aim of enhancing the response to antiangiogenic therapy in cancer patients and mouse models. This review introduces a comprehensive understanding of the mechanisms and biomarkers associated with the evasion of antiangiogenic therapy in cancer, providing an outlook for developing more effective approaches to promote the therapeutic efficacy of antiangiogenic therapy.

m6A modification: recent advances, anticancer targeted drug discovery and beyond.

Abnormal N6-methyladenosine (m6A) modification is closely associated with the occurrence, development, progression and prognosis of cancer, and aberrant m6A regulators have been identified as novel anticancer drug targets. Both traditional medicine-related approaches and modern drug discovery platforms have been used in an attempt to develop m6A-targeted drugs. Here, we provide an update of the latest findings on m6A modification and the critical roles of m6A modification in cancer progression, and we summarize rational sources for the discovery of m6A-targeted anticancer agents from traditional medicines and computer-based chemosynthetic compounds. This review highlights the potential agents targeting m6A modification for cancer treatment and proposes the advantage of artificial intelligence (AI) in the discovery of m6A-targeting anticancer drugs. Three stages of m6A-targeting anticancer drug discovery: traditional medicine-based natural products, modern chemical modification or synthesis, and artificial intelligence (AI)-assisted approaches for the future.

Angiogenesis-Inhibitory Piperidine Alkaloids from the Leaves of Microcos paniculata.

Eight new 2,6-disubstituted piperidin-3-ol alkaloids (1-8), featuring a C10 unsaturated alkyl side chain, together with three previously reported analogues (9-11) were isolated from the leaves of medicinal plant Microcos paniculata. Their structures and absolute configurations were elucidated unambiguously by means of 1D and 2D NMR spectroscopic data analysis, modified Mosher's method, Snatzke's method, and quantum chemical electronic circular dichroism (ECD) calculations, as well as single-crystal X-ray crystallography. The isolates were evaluated for their antiangiogenic effects on human umbilical vein endothelial cells (HUVECs). Compound 2 displayed an inhibitory effect on tube formation of HUVECs in a concentration-dependent manner.

3'-Oxo-tabernaelegantine A (OTNA) selectively relaxes pulmonary arteries by inhibiting AhR.

BACKGROUND: Pulmonary arterial hypertension (PAH), characterized by pulmonary artery constriction and vascular remodeling, has a high mortality rate. New drugs for the treatment of PAH urgently need to be developed. PURPOSE: This study was designed to investigate the vasorelaxant activity of OTNA in isolated pulmonary arteries, and explore its molecular mechanism. METHODS: Pulmonary arteries and thoracic aortas were isolated from mice, and vascular tone was tested with a Wire Myograph System. Nitric oxide levels were determined with DAF-FM DA and DAX-J2™ Red. Cellular thermal shift assays, microscale thermophoresis, and molecular docking were used to identify the interaction between OTNA and aryl hydrocarbon receptor (AhR). The levels of PI3K, p-PI3K, Akt, p-Akt, eNOS, p-eNOS, and AhR were analyzed by Western blotting. RESULTS: OTNA selectively relaxed the isolated pulmonary artery rings in an endothelium-dependent manner. Mechanistic study showed that OTNA induced NO production through activation of the PI3K/Akt/eNOS pathway in endothelial cells. Furthermore, we also found that OTNA directly bound to AhR and activated the PI3K/Akt/eNOS pathway to dilate pulmonary arteries by inhibiting AhR. CONCLUSIONS: OTNA relaxes pulmonary arteries by antagonizing AhR. This study provides a new natural antagonist of AhR as a promising lead compound for PAH treatment.

Notoginsenoside R1 activates the Ang2/Tie2 pathway to promote angiogenesis.

BACKGROUND: Therapeutic angiogenesis is a novel strategy for the treatment of ischemic diseases that involves promotion of angiogenesis in ischemic tissues via the use of proangiogenic agents. However, effective proangiogenic drugs that activate the Ang2/Tie2 signaling pathway remain scarce. PURPOSE: We aimed to investigate the proangiogenic activity of notoginsenoside R1 (NR1) isolated from total saponins of Panax notoginseng with regard to activation of the Ang2/Tie2 signaling pathway. METHODS: We examined the proangiogenic effects of NR1 by assessing the effects of NR1 on the proliferation, migration, invasion and tube formation of human umbilical vein endothelial cells (HUVECs). The aortic ring assay and vascular endothelial growth factor receptor inhibitor (VRI)-induced vascular regression in the zebrafish model were used to confirm the proangiogenic effects of NR1 ex vivo and in vivo. Furthermore, the molecular mechanism was investigated by Western blot analysis. RESULTS: We found that NR1 promoted the proliferation, mobility and tube formation of HUVECs in vitro. NR1 also increased the number of sprouting vessels in rat aortic rings and rescued VRI-induced vascular regression in zebrafish. NR1-induced angiogenesis was dependent on Tie2 receptor activation mediated by increased autocrine Ang2 in HUVECs, and inhibition of the Ang2/Tie2 pathway abrogated the proangiogenic effects of NR1. CONCLUSIONS: Our results suggest that NR1 promotes angiogenesis by activating the Ang2/Tie2 signaling pathway. Thus, NR1-induced activation of the Ang2/Tie2 pathway is an effective proangiogenic approach. NR1 may be useful agent for the treatment of ischemic diseases.

Ginsenoside F1 promotes angiogenesis by activating the IGF-1/IGF1R pathway.

Ischemic stroke is one of the most lethal and highly disabling diseases that seriously affects the human health and quality of life. A therapeutic angiogenic strategy has been proposed to alleviate ischemia-induced injury by promoting angiogenesis and improving cerebrovascular function in the ischemic regions. The insulin-like growth factor 1 (IGF-1)/insulin-like growth factor 1 receptor (IGF1R) axis is crucial for cerebral angiogenesis and neurogenesis. However, effective drugs that prevent cerebral ischemic injury by inducing cerebral angiogenesis via activation of the IGF1R pathway are lacking. Here, we screened a pro-angiogenic agent ginsenoside F1 (GF1), a ginseng saponin isolated from a traditional Chinese medicine that was widely used in ischemic stroke treatment. It promoted the proliferation, mobility and tube formation of human umbilical vein endothelial cells and human brain microvascular endothelial cells, as well as pericytes recruitment to the endothelial tubes. GF1 stimulated vessel sprouting in the rat arterial ring and facilitated neovascularization in chicken embryo chorioallantoic membrane (CAM). In the in vivo experiments, GF1 rescued the axitinib-induced vascular defect in zebrafish. It also increased the microvessel density (MVD) and improved focal cerebral blood perfusion in the rat middle cerebral artery occlusion (MCAO) model. Mechanism studies revealed that GF1-induced angiogenesis depended on IGF1R activation mediated by the autocrine IGF-1 loop in endothelial cells. Based on our findings, GF1-induced activation of the IGF-1/IGF1R pathway to promote angiogenesis is an effective approach to alleviate cerebral ischemia, and GF1 is a potential agent that improves cerebrovascular function and promotes recovery from ischemic stroke.

Fibroblast Activation Protein α Activated Tripeptide Bufadienolide Antitumor Prodrug with Reduced Cardiotoxicity.

Bufadienolides are the major pharmacologic constituents of traditional Chinese medicine Chan'su, which is frequently used clinically for cancer treatment in China. Motivated by reducing or avoiding the cardiac toxicity of bufadienolides, we have designed, synthesized, and evaluated the fibroblast activation protein α (FAPα) activated tripeptide arenobufagin prodrugs with the purpose of improving the safety of arenobufagin (a representative bufadienolide). Among these FAPα-activated prodrugs, 3f exhibited the best hydrolytic efficiency by recombinant human FAPα (rhFAPα) and was activated in tumors. The LD50 of 3f was 6.5-fold higher than that of arenobufagin. We also observed that there are nonapparent changes in echocardiography, pathological section of cardiac muscle, and the lactate dehydrogenase activities (LDH) in 3f-treatment tumor-bearing mice, even when the dose reached 3 times the amount of parent drug arenobufagin that was used. Compound 3f also exhibits significant antitumor activity in vitro and in vivo. The improved safety profile and favorable anticancer properties of 3f warrant further studies of the potential clinical implications. Our study suggests that FAPα prodrug strategy is an effective approach for successful increasing the therapeutic window of bufadienolides.

Uncaria alkaloids reverse ABCB1-mediated cancer multidrug resistance.

The overexpression of ATP-binding cassette (ABC) transporters is the main cause of cancer multidrug resistance (MDR), which leads to chemotherapy failure. Uncaria alkaloids are the major active components isolated from uncaria, which is a common Chinese herbal medicine. In this study, the MDR-reversal activities of uncaria alkaloids, including rhynchophylline, isorhynchophylline, corynoxeine, isocorynoxeine (Icory), hirsutine and hirsuteine, were screened; they all exhibited potent reversal efficacy when combined with doxorubicin. Among them, Icory significantly sensitized ABCB1-overexpressing HepG2/ADM and MCF-7/ADR cells to vincristine, doxorubicin and paclitaxel, but not to the non-ABCB1 substrate cisplatin. Noteworthy, Icory selectively reversed ABCB1-overexpressing MDR cancer cells but not ABCC1- or ABCG2-mediated MDR. Further mechanistic study revealed that Icory increased the intracellular accumulation of doxorubicin in ABCB1-overexpressing cells by blocking the efflux function of ABCB1. Instead of inhibiting ABCB1 expression and localization, Icory acts as a substrate of the ABCB1 transporter by competitively binding to substrate binding sites. Collectively, these results indicated that Icory reversed ABCB1-mediated MDR by suppressing its efflux function, and it would be beneficial to increase the efficacy of these types of uncaria alkaloids and develop them to be selective ABCB1-mediated MDR-reversal agents.

Five new koumine-type alkaloids from the roots of Gelsemium elegans.

Five new koumine-type alkaloids (1-5) along with six known ones were isolated from the roots of Gelsemium elegans. Their structures with absolute configurations were elucidated on the basis of NMR spectroscopy and electronic circular dichroism spectral analyses. The inhibitory effects of compounds 1-11 on the viability of three tumor cell lines (A-649, HepG2, and HuH7) were evaluated by the MTT assay.

LPS/TLR4 Signaling Enhances TGF-ß Response Through Downregulating BAMBI During Prostatic Hyperplasia.

Compelling evidence suggests that benign prostatic hyperplasia (BPH) development involves accumulation of mesenchymal-like cells derived from the prostatic epithelium by epithelial-mesenchymal transition (EMT). Transforming growth factor (TGF)-ß induces EMT phenotypes with low E-cadherin and high vimentin expression in prostatic epithelial cells. Here we report that LPS/TLR4 signalling induces down-regulation of the bone morphogenic protein and activin membrane-bound inhibitor (BAMBI), which enhances TGF-ß signalling in the EMT process during prostatic hyperplasia. Additionally, we found that the mean TLR4 staining score was significantly higher in BPH tissues with inflammation compared with BPH tissues without inflammation (5.13 ± 1.21 and 2.96 ± 0.73, respectively; P < 0.001). Moreover, patients with inflammatory infiltrate were more likely to have a higher age (P = 0.020), BMI (P = 0.026), prostate volume (P = 0.024), total IPSS score (P = 0.009) and IPSS-S (P < 0.001). Pearson's correlation coefficient and multiple regression analyses demonstrated that TLR4 mRNA expression level was significantly positively associated with age, BMI, serum PSA levels, urgency and nocturia subscores of IPSS in the inflammatory group. These findings provide new insights into the TLR4-amplified EMT process and the association between TLR4 levels and storage LUTS, suggesting chronic inflammation as vital to the pathogenesis of BPH.

Antiproliferative triterpenoid saponins from the stem of Psychotria sp.

Six new triterpenoid saponins, psychotrianosides A-F (1-6), and two known triterpenoid saponins, psychotrianoside G (7) and ardisianoside D (8), were isolated from Psychotria sp. Their structures were determined mainly by spectroscopic methods. The cytotoxic activities of 1-8 against five human cancer cell lines (MDA-MB-231, MCF-7, MCF-7/ADM, HepG2, and HepG2/ADM) are reported for the first time. Psychotrianoside C (3) showed the most potent antiproliferative activity among these saponins, and the IC50 value of 3 against MDA-MB-231 was 2.391 ± 0.161 µM. Compound 3 was also found to induce apoptosis.

Arenobufagin, a natural bufadienolide from toad venom, induces apoptosis and autophagy in human hepatocellular carcinoma cells through inhibition of PI3K/Akt/mTOR pathway.

Hepatocellular carcinoma (HCC) is a deadly form of cancer without effective chemotherapy so far. Currently, only sorafenib, a multitargeted tyrosine kinase inhibitor, slightly improves survival in HCC patients. In searching for natural anti-HCC components from toad venom, which is frequently used in the treatment of liver cancer in traditional Chinese medicine, we discovered that arenobufagin, a bufadienolide from toad venom, had potent antineoplastic activity against HCC HepG2 cells as well as corresponding multidrug-resistant HepG2/ADM cells. We found that arenobufagin induced mitochondria-mediated apoptosis in HCC cells, with decreasing mitochondrial potential, as well as increasing Bax/Bcl-2 expression ratio, Bax translocation from cytosol to mitochondria. Arenobufagin also induced autophagy in HepG2/ADM cells. Autophagy-specific inhibitors (3-methyladenine, chloroquine and bafilomycin A1) or Beclin1 and Atg 5 small interfering RNAs (siRNAs) enhanced arenobufagin-induced apoptosis, indicating that arenobufagin-mediated autophagy may protect HepG2/ADM cells from undergoing apoptotic cell death. In addition, we observed the inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway by arenobufagin. Interestingly, inhibition of mTOR by rapamycin or siRNA duplexes augmented arenobufagin-induced apoptosis and autophagy. Finally, arenobufagin inhibited the growth of HepG2/ADM xenograft tumors, which were associated with poly (ADP-ribose) polymerase cleavage, light chain 3-II activation and mTOR inhibition. In summary, we first demonstrated the antineoplastic effect of arenobufagin on HCC cells both in vitro and in vivo. We elucidated the underlying antineoplastic mechanisms of arenobufagin that involve cross talk between apoptosis and autophagy via inhibition of the PI3K/Akt/mTOR pathway. This study may provide a rationale for future clinical application using arenobufagin as a chemotherapeutic agent for HCC.

Dauricine can inhibit the activity of proliferation of urinary tract tumor cells.

OBJECTIVE: To explore the anti-tumor effects of asiatic moonseed rhizome extraction-dauricine on bladder cancer EJ cell strain, prostate cancer PC-3Mcell strain and primary cell culture system. METHODS: The main effective component-phenolic alkaloids ofMenispermum dauricum was extracted and separated from asiatic moonseed rhizome by chemical method. MTT method was used to detect dauricine anti-tumor effect. RESULTS: Dauricine had an obvious proliferation inhibition effect on the main tumor cells in urinary system. The minimum drug sensitivity concentration was between 3.81-5.15 µg/mL, and the inhibition ratio increased with the increase of concentration. CONCLUSIONS: Dauricine, the main effective component extracted from asiatic moonseed rhizome, had a good inhibition effect on tumor cells in urinary system. At the same time, Dauricine has certain inhibition effects on the primary cultured tumor cell.

Cytotoxic dimeric indole alkaloids from Catharanthus roseus.

Three new dimeric indole alkaloids (1-3), together with five known ones (4-8), were isolated from the whole plants of Catharanthus roseus. The structures and absolute configurations of new compounds were elucidated by means of NMR and CD analyses. All these compounds were evaluated for their in vitro cytotoxic activities against human breast cancer cell line MDA-MB-231.

Icaritin induces apoptosis of HepG2 cells via the JNK1 signaling pathway independent of the estrogen receptor.

Chinese herbs have become a focus in cancer treatment. Icaritin, a prenylflavonoid derivative from Chinese herbs of the Epimedium genus, has selective estrogen receptor (ER) modulating activity. This study evaluates the effects of icaritin on the apoptosis of HepG2 hepatocellular carcinoma cells. Icaritin (at 5-50 µM) induced apoptosis of HepG2 cells. Few changes in icaritin-induced apoptosis were observed after pretreatment with ICI182780. Consistent with apoptosis induction, icaritin increased the Bax/Bcl-2 ratio and caspase-3 activation in HepG2 cells. Furthermore, icaritin was capable of stimulating the c-Jun N-terminal kinase 1 (JNK1), but not the JNK2, ERK1/2, and p38 subgroups of the mitogen-activated protein kinase (MAPK) family. Coincidently, icaritin-induced cell apoptosis was abolished by SP600125, a specific inhibitor for JNK. Collectively, our results suggest a novel pro-apoptotic activity of icaritin mediated via the JNK1 signaling pathway that is not associated with ER in HepG2 cells.

Ancient human genome sequence of an extinct Palaeo-Eskimo.

We report here the genome sequence of an ancient human. Obtained from approximately 4,000-year-old permafrost-preserved hair, the genome represents a male individual from the first known culture to settle in Greenland. Sequenced to an average depth of 20x, we recover 79% of the diploid genome, an amount close to the practical limit of current sequencing technologies. We identify 353,151 high-confidence single-nucleotide polymorphisms (SNPs), of which 6.8% have not been reported previously. We estimate raw read contamination to be no higher than 0.8%. We use functional SNP assessment to assign possible phenotypic characteristics of the individual that belonged to a culture whose location has yielded only trace human remains. We compare the high-confidence SNPs to those of contemporary populations to find the populations most closely related to the individual. This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit.

Chronic prostatitis presenting with dysfunctional voiding and effects of pelvic floor biofeedback treatment.

OBJECTIVE: To investigate the features of chronic prostatitis presenting with dysfunctional voiding (DV) and the effects of pelvic floor biofeedback (PFB). PATIENTS AND METHODS: The study included 21 patients, diagnosed by having symptoms for > or =3 months, including urinary frequency and urgency, voiding difficulty, upper abdominal or perineal discomfort, and with a score of > or =1 on the first and second part of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI). Patients with bacterial prostatitis, urethritis, interstitial cystitis, urethral stricture and neurogenic bladder were excluded. All patients had a urodynamic examination, to assess the uroflow curve, maximum urinary flow rate (Q(max)), maximum detrusor pressure during the storage phase (P(det.max)), maximum urethral pressure (MUP) and the maximum urethral closure pressure (MUCP) were recorded. PFB was carried out in patients with non-neurogenic detrusor sphincter dyssynergia, and the effects evaluated after 10 weeks. RESULTS: Before and after PFB treatment the mean (sd) Q(max), P(det.max), MUP, MUCP were 8.2 (4.1) vs 15.1 (7.3) mL/s, 125.1 (75.3) vs 86.3 (54.2) cmH(2)O, 124.3 (23.3) vs 65.4 (23.0) cmH(2)O and 101.5 (43.6) vs 43.5 (16.7) cmH(2)O, all significantly different (P < 0.05). The respective differences in the pain, urination and life impact subdomain scores, and total scores, of the NIH-CPSI were 4.0 (2.0) vs 2.2 (1.7), 7.9 (2.1) vs 2.2 (1.9), 9.6 (2.7) vs 2.9 (2.6) and 21.7 (4.8) vs 8.4 (4.6), and all differences were significant (P < 0.05). CONCLUSIONS: There might be DV in patients with chronic prostatitis and lower urinary tract symptoms. Urodynamics showed a low Q(max) and increasing intravesical pressure and, in some patients, increasing urethral pressure. Urodynamics could be used to help in the diagnosis, and to select the most appropriate treatment. PFB had satisfactory short-term effects on these patients.