Antibiotic anisomycin selectively targets leukemia cell lines and patient samples through suppressing Wnt/β-catenin signaling

Understanding the Artemia Salina (Brine Shrimp) Test: Pharmacological Significance and Global Impact

BACKGROUND

The microplate benchtop brine shrimp test (BST) has been widely used for screening and bio-guided isolation of many active compounds, including natural products. Although the interpretation given to the results appears dissimilar, our findings suggest a correlation between positive results with a specific mechanism of action.

OBJECTIVE

This study aimed to evaluate drugs belonging to fifteen pharmacological categories having diverse mechanisms of action and carry out a bibliometric analysis of over 700 citations related to microwell BST.

METHODS

Test compounds were evaluated in a serial dilution on the microwell BST using healthy nauplii of Artemia salina and after 24 hrs of exposition, the number of alive and dead nauplii was determined, and the LC50 was estimated. A metric study regarding the citations of the BST miniaturized method, sorted by type of documents cited, contributing country, and interpretation of results was conducted on 706 selected citations found in Google Scholar.

RESULTS

Out of 206 drugs tested belonging to fifteen pharmacological categories, twenty-six showed LC50 values <100 μM, most of them belonging to the category of antineoplastic drugs; compounds with different therapeutical uses were found to be cytotoxic as well. A bibliometric analysis showed 706 documents citing the miniaturized BST; 78% of them belonged to academic laboratories from developing countries located on all continents, 63% interpreted their results as cytotoxic activity and 35% indicated general toxicity assessment.

CONCLUSION

BST is a simple, affordable, benchtop assay, capable of detecting cytotoxic drugs with specific mechanisms of action, such as protein synthesis inhibition, antimitotic, DNA binding, topoisomerase I inhibitors, and caspases cascade interfering drugs. The microwell BST is a technique that is used worldwide for the bio-guided isolation of cytotoxic compounds from different sources.

Anisomycin inhibits the activity of human ovarian cancer stem cells via regulating antisense RNA NCBP2-AS2/MEK/ERK/STAT3 signaling

BACKGROUND

Ovarian cancer stem cells (OCSCs) are the main cause of relapse and drug resistance in patients with ovarian cancer. Anisomycin has been shown to be an effective antitumor agent, but its mechanism of action in ovarian cancer remains elusive.

METHODS

CD44+/CD133+ human OCSCs were isolated from human ovarian cancer tissues. OCSCs were interfered with using anisomycin and specific small-interfering RNA (siRNA). Microarray assay, MTT, in vivo tumorigenic experiments, transwell assay, cell cycle assay, colony formation assay, angiogenesis assay, and hematoxylin and eosin staining were used to detect the mechanism of anisomycin with respect to inhibiting the activity of OCSCs. Expression of the NCBP2-AS2/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK)/signal transducer and activator of transcription 3 (STAT3) pathway was examined using western blotting, a quantitative real-time PCR (RT-qPCR) and immunofluorescence staining. Bioinformatics analysis was used for predictive analysis of NCBP2-AS2 expression in urogenital tumors.

RESULTS

Microarray analysis showed that treatment with anisomycin significantly decreased the expression of antisense RNA NCBP2-AS2 in OCSCs. In vitro cellular experiments showed that interfering with endogenous antisense RNA NCBP2-AS2 using siRNA distinctly inhibited the proliferation, migration and angiogenesis of OCSCs, whereas in vivo animal experiments revealed decreased tumorigenesis in nude mice. Moreover, the results of RT-qPCR and western blotting demonstrated that both anisomycin treatment and NCBP2-AS2 silencing led to significant reductions in the mRNA and protein expression levels of NCBP2-AS2, MEK, ERK and STAT3. From a bioinformatic point of view, antisense RNA NCBP2-AS2 exhibited significantly differential expression between urogenital tumors and normal controls, and a similar expression pattern was found in the genes NCBP2, RPL35A, DNAJC19 and ECE2, which have similarity to NCBP2-AS2.

CONCLUSIONS

Anisomycin suppresses the in vivo and in vitro activity of human OCSCs by downregulating the antisense RNA NCBP2-AS2/MEK/ERK/STAT3 signaling pathway, whereas the antisense RNA NCBP2-AS2 and genes with similarity have the potential to serve as markers for clinical diagnosis and prognosis of urogenital tumors.

Niclosamide is a potential candidate for the treatment of chemo-resistant osteosarcoma

Chemotherapy is the main treatment option for advanced osteosarcoma, which is the most common type of primary bone malignancy. However, patients develop resistance rapidly and many succumb to the disease. Niclosamide, an anthelmintic drug, has been recently identified to display potent and selective anti-cancer activity. In this work, we show that niclosamide at sub-micromolar concentrations inhibits proliferation and migration, and induces apoptosis in both parental and chemo-resistant osteosarcoma cells, with much less toxicity in normal osteoblastic cells. Interestingly, chemo-resistant osteosarcoma cells are more sensitive to niclosamide compared to parental cells. We further identify that inhibition of β-catenin is the underlying mechanism of niclosamide's action in osteosarcoma cells. In addition, we reveal that chemo-resistant osteosarcoma cells display increased β-catenin activity compared to parental cells, which might explain the hypersensitivity of chemo-resistant cells to niclosamide. Our work provides pre-clinical evidence that niclosamide can be repurposed for treating osteosarcoma. Our findings also suggest the therapeutic value of β-catenin to overcome osteosarcoma chemo-resistance.

Modulation of the p38 MAPK Pathway by Anisomycin Promotes Ferroptosis of Hepatocellular Carcinoma through Phosphorylation of H3S10

Hepatocellular carcinoma (HCC) is a prevalent malignant tumor worldwide. Ferroptosis is emerging as an effective target for tumor treatment as it has been shown to potentiate cell death in some malignancies. However, it remains unclear whether histone phosphorylation events, an epigenetic mechanism that regulates transcriptional expression, are involved in ferroptosis. Our study found that supplementation with anisomycin, an agonist of p38 mitogen-activated protein kinase (MAPK), induced ferroptosis in HCC cells, and the phosphorylation of histone H3 on serine 10 (p-H3S10) was participated in anisomycin-induced ferroptosis. To investigate the anticancer effects of anisomycin-activated p38 MAPK in HCC, we analyzed cell viability, colony formation, cell death, and cell migration in Hep3B and HCCLM3 cells. The results showed that anisomycin could significantly suppress HCC cell colony formation and migration and induce HCC cell death. The hallmarks of ferroptosis, such as abnormal accumulation of iron and elevated levels of lipid peroxidation and malondialdehyde, were detected to confirm the ability of anisomycin to promote ferroptosis. Furthermore, coincubation with SB203580, an inhibitor of activated p38 MAPK, partially rescued anisomycin-induced ferroptosis. And the levels of p-p38 MAPK and p-H3S10 were successively increased by anisomycin treatment. The relationship between p-H3S10 and ferroptosis was revealed by ChIP sequencing. The reverse transcription PCR and immunofluorescence results showed that NCOA4 was upregulated both in mRNA and protein levels after anisomycin treatment. And by C11-BODIPY staining, we found that anisomycin-induced lipid reactive oxygen species was reduced after NCOA4 knockdown. In conclusion, the anisomycin-activated p38 MAPK promoted ferroptosis of HCC cells through H3S10 phosphorylation.

The Wnt/β-catenin signalling pathway in Haematological Neoplasms

Leukaemia and lymphoma are common malignancies. The Wnt pathway is a complex network of proteins regulating cell proliferation and differentiation, as well as cancer development, and is divided into the Wnt/β-catenin signalling pathway (the canonical Wnt signalling pathway) and the noncanonical Wnt signalling pathway. The Wnt/β-catenin signalling pathway is highly conserved evolutionarily, and activation or inhibition of either of the pathways may lead to cancer development and progression. The aim of this review is to analyse the mechanisms of action of related molecules in the Wnt/β-catenin pathway in haematologic malignancies and their feasibility as therapeutic targets.

Signaling pathways in the regulation of cancer stem cells and associated targeted therapy

Cancer stem cells (CSCs) are defined as a subpopulation of malignant tumor cells with selective capacities for tumor initiation, self-renewal, metastasis, and unlimited growth into bulks, which are believed as a major cause of progressive tumor phenotypes, including recurrence, metastasis, and treatment failure. A number of signaling pathways are involved in the maintenance of stem cell properties and survival of CSCs, including well-established intrinsic pathways, such as the Notch, Wnt, and Hedgehog signaling, and extrinsic pathways, such as the vascular microenvironment and tumor-associated immune cells. There is also intricate crosstalk between these signal cascades and other oncogenic pathways. Thus, targeting pathway molecules that regulate CSCs provides a new option for the treatment of therapy-resistant or -refractory tumors. These treatments include small molecule inhibitors, monoclonal antibodies that target key signaling in CSCs, as well as CSC-directed immunotherapies that harness the immune systems to target CSCs. This review aims to provide an overview of the regulating networks and their immune interactions involved in CSC development. We also address the update on the development of CSC-directed therapeutics, with a special focus on those with application approval or under clinical evaluation.

Anisomycin inhibits angiogenesis, growth, and survival of triple-negative breast cancer through mitochondrial dysfunction, AMPK activation, and mTOR inhibition

Aberrant upregulation of mitochondrial biogenesis is observed in breast cancer and holds potential therapeutic option. In our work, we showed that inhibition of mitochondrial function by anisomycin is effective against triple-negative breast cancer (TNBC). Anisomycin inhibits growth and induces caspase-dependent apoptosis in a panel of TNBC cell lines. Of note, anisomycin at a tolerable dose remarkably suppresses growth of TNBC in mice. In addition, anisomycin effectively targets breast cancer angiogenesis through inhibiting capillary network formation, migration, proliferation, and survival. Mechanistic studies show that although anisomycin activates p38 and JNK, their activations are not required for anisomycin's action. In contrast, anisomycin inhibits mitochondrial respiration, and decreases mitochondrial membrane potential and adenosine triphosphate (ATP) level. The inhibitory effect of anisomycin is significantly reversed in mitochondria respiration-deficient ρ0 cells. As a consequence, anisomycin activates AMPK and inhibits mammalian target-of-rapamycin signaling pathways. Our work demonstrated that anisomycin is a useful addition to the treatment armamentarium for TNBC.

Anisomycin is active in preclinical models of pediatric acute myeloid leukemia via specifically inhibiting mitochondrial respiration

The poor outcomes in acute myeloid leukemia (AML) necessitate new treatments. In this work, we identified that anisomycin is a potential selective anti-AML candidate, particularly for those with FLT3-ITD mutation. We found that anisomycin potently inhibited proliferation and induced apoptosis in multiple AML cell lines. Anisomycin was effective in targeting progenitor cells isolated from all tested pediatric AML patients, while sparing normal counterparts. Using AML xenograft mouse models, anisomycin exhibited inhibitory effect on tumor growth throughout the whole duration without causing toxicity in mice. The combination of anisomycin with standard of care drugs is synergistic and selective in AML cell culture system and mouse model. In addition, FLT3-ITD cells were more sensitive to anisomycin than FLT3 WT cells. Mechanistic studies revealed that anisomycin acted on AML in a p38-independent manner. We found that anisomycin decreased mitochondrial respiration by disrupting complex I activity, leading to intracellular oxidative stress. AML ρ⁰ cells that lack of mitochondrial respiration exhibited resistance to anisomycin. Finally, we showed that mitochondrial biogenesis contributes to differential sensitivity of FLT3-ITD and FLT3 WT cells to anisomycin. Our work is the first to systematically demonstrate that anisomycin is a useful addition to the treatment armamentarium for AML. Our findings highlight the therapeutic value of mitochondrial respiration inhibition in AML patients harboring FLT3-ITD mutation.

Anisomycin induces hair cell death and blocks supporting cell proliferation in zebrafish lateral line neuromast

Ototoxicity of drugs is an important inducement for hearing loss. Anisomycin is a candidate drug for parasite, cancer, immunosuppression, and mental disease. However, the ototoxicity of anisomycin has not been examined. In this study, the ototoxicity of anisomycin was evaluated using zebrafish lateral line. We found the zebrafish treated with anisomycin during lateral line development could inhibit hair cell formation in a time- and dose-dependent manner. After neuromasts are mature with differentiated hair cells by 5 day post-fertilization, anisomycin could induce hair cell loss effectively through chronic exposure rather than acute exposure. TUNEL assay and qPCR of apoptosis related genes tp53, casp8, casp3a, and casp3b indicated that cell apoptotic was induced by chronic anisomycin exposure. Furthermore, knocking down tp53 with antisense morpholino could attenuate the hair cell loss induced by anisomycin. In addition, we found that anisomycin chronic exposure also inhibited the proliferation of supporting cell. Together, these results indicate that chronic anisomycin exposure could induce hair cell death and block supporting cell proliferation, which causes hair cell loss in zebrafish neuromast. This study provides primary ototoxicity evaluation for anisomycin.

Integrative Analysis of a Novel Eleven-Small Nucleolar RNA Prognostic Signature in Patients With Lower Grade Glioma

Objective

The present study used the RNA sequencing (RNA-seq) dataset to identify prognostic snoRNAs and construct a prognostic signature of The Cancer Genome Atla (TCGA) lower grade glioma (LGG) cohort, and comprehensive analysis of this signature.

Methods

RNA-seq dataset of 488 patients from TCGA LGG cohort were included in this study. Comprehensive analysis including function enrichment, gene set enrichment analysis (GSEA), immune infiltration, cancer immune microenvironment, and connectivity map (CMap) were used to evaluate the snoRNAs prognostic signature.

Results

We identified 21 LGG prognostic snoRNAs and constructed a novel eleven-snoRNA prognostic signature for LGG patients. Survival analysis suggests that this signature is an independent prognostic risk factor for LGG, and the prognosis of LGG patients with a high-risk phenotype is poor (adjusted P = 0.003, adjusted hazard ratio = 2.076, 95% confidence interval = 1.290–3.340). GSEA and functional enrichment analysis suggest that this signature may be involved in the following biological processes and signaling pathways: such as cell cycle, Wnt, mitogen-activated protein kinase, janus kinase/signal transducer and activator of tran-ions, T cell receptor, nuclear factor-kappa B signaling pathway. CMap analysis screened out ten targeted therapy drugs for this signature: 15-delta prostaglandin J2, MG-262, vorinostat, 5155877, puromycin, anisomycin, withaferin A, ciclopirox, chloropyrazine and megestrol. We also found that high- and low-risk score phenotypes of LGG patients have significant differences in immune infiltration and cancer immune microenvironment.

Conclusions

The present study identified a novel eleven-snoRNA prognostic signature of LGG and performed a integrative analysis of its molecular mechanisms and relationship with tumor immunity.

Analysis of differentially expressed genes responsible for the suppressive effect of anisomycin on cell proliferation of DLD-1 cells

Anisomycin is used as a chemical compound that possesses c-Jun N-terminal kinase (JNK)-activating effects. Recently, the potent anti-tumor effects of anisomycin have received much attention. In addition to its JNK-activating effects, anisomycin has been reported to affect gene expression in osteosarcoma, leukemia, hepatocellular carcinoma, ovarian cancer and other cancers. We previously demonstrated that anisomycin induced the degradation of transcription factor GATA-6 in DLD-1 cells (a colorectal cancer cell line) and inhibited their proliferation. However, the details of the gene network involved in the process remain unclear. In this study, we conducted an RNA-seq analysis of differentially expressed genes (DEGs) in anisomycin-treated DLD-1 cells to identify the molecular process of growth-suppressive genes. We found that LAMB3, which regulates cell adhesion and migration, and NFKB2 were down-regulated by anisomycin. In addition, the mRNA expression of several tumor suppressor genes (ATF3, ERRFI1, KLF6, and AKAP12) was transiently enhanced at 3 h after anisomycin treatment. These results suggest that anisomycin blocks a PI3K/Akt-signaling cascade to lead to the suppression of cell growth.

Expression level of long non-coding RNA colon adenocarcinoma hypermethylated serves as a novel prognostic biomarker in patients with thyroid carcinoma

The present study attempts to identify the prognostic value and potential mechanism of action of colorectal adenocarcinoma hypermethylated (CAHM) in thyroid carcinoma (THCA) by using the RNA sequencing (RNA-seq) dataset from The Cancer Genome Atlas (TCGA). The functional mechanism of CAHM was explored by using RNA-seq dataset and multiple functional enrichment analysis approaches. Connectivity map (CMap) online analysis tool was also used to predict CAHM targeted drugs. Survival analysis suggests that THCA patients with high CAHM expression have lower risk of death than the low CAHM expression (log-rank P=0.022, adjusted P=0.011, HR = 0.187, 95% confidence interval (CI) = 0.051–0.685). Functional enrichment of CAHM co-expression genes suggests that CAHM may play a role in the following biological processes: DNA repair, cell adhesion, DNA replication, vascular endothelial growth factor receptor, Erb-B2 receptor tyrosine kinase 2, ErbB and thyroid hormone signaling pathways. Functional enrichment of differentially expressed genes (DEGs) between low- and high-CAHM phenotype suggests that different CAHM expression levels may have the following differences in biological processes in THCA: cell adhesion, cell proliferation, extracellular signal-regulated kinase (ERK) 1 (ERK1) and ERK2 cascade, G-protein coupled receptor, chemokine and phosphatidylinositol-3-kinase-Akt signaling pathways. Connectivity map have identified five drugs (levobunolol, NU-1025, quipazine, anisomycin and sulfathiazole) for CAHM targeted therapy in THCA. Gene set enrichment analysis (GSEA) suggest that low CAHM phenotype were notably enriched in p53, nuclear factor κB, Janus kinase-signal transducer and activators of transcription, tumor necrosis factor, epidermal growth factor receptor and other signaling pathways. In the present study, we have identified that CAHM may serve as novel prognostic biomarkers for predicting overall survival (OS) in patients with THCA.

Anisomycin sensitizes non-small-cell lung cancer cells to chemotherapeutic agents and epidermal growth factor receptor inhibitor via suppressing PI3K/Akt/mTOR

The poor outcomes in advanced non-small-cell lung cancer (NSCLC) necessitate new treatments. Recent studies emphasize anisomycin as a promising anti-cancer drug candidate. In this work, we systematically investigated the efficacy of anisomycin alone and its combination with the standard-of-care drugs in NSCLC. We showed that anisomycin inhibited growth, migration, and survival in NSCLC cells regardless of genetic mutation status, and to a greater extent than in normal lung epithelial cells. Isobologram analysis showed that the combination of anisomycin with cisplatin, paclitaxel, or gefitinib was synergistic in NSCLC but not normal lung cells. We further demonstrated that anisomycin inhibited NSCLC growth in mice. The combination of anisomycin with cisplatin was more effective than cisplatin alone and completely arrested NSCLC growth throughout the whole duration of treatment. JNK and p38 MAPK were not required for anisomycin's action. In contrast, anisomycin inhibits PI3K/Akt/mTOR pathway. Overexpression of constitutively active Akt reversed the pro-apoptotic effect of anisomycin. Our work demonstrates the selective anti-NSCLC activity of anisomycin via suppressing PI3K/Akt/mTOR. Our findings provide preclinical evidence to initialize the clinical trial of using anisomycin to sensitize NSCLC to current therapy.

Targeting of the Alox12-12-HETE in Blast Crisis Chronic Myeloid Leukemia Inhibits Leukemia Stem/Progenitor Cell Function

Introduction

Chronic myeloid leukemia (CML) is a myeloid malignancy characterized by the oncogene BCR-ABL. CML responds well to therapy targeting BCR-ABL in the chronic phase but is resistant to treatment when it progresses to the blast phase (BP). This study attempted to address whether arachidonate 12-lipoxygenase (Alox12) confers to CML drug resistance.

Materials and Methods

We analyzed the expression of Alox12 using Western blotting, ELISA, and RT-PCR methods. Loss of functional analysis was performed using cellular activity assays on CML and normal hematopoietic stem/progenitor cells (HSPCs).

Results

Alox12 and 12-Hydroxyeicosatetraenoic acid (12-HETE) are overexpressed in BP-CML but not HSPCs, and that Alox12-12-HETE axis is regulated by BCR-ABL. The Alox12-12-HETE axis is required for CML. Specific Alox12 inhibitor inhibits colony formation, survival, and self-renewal capacity in BP-CML HSPCs, and to a significantly greater extent than in normal HSPCs. Of note, the Alox12 inhibitor significantly augments dasatinib’s efficacy in BP-CML HSPCs. Mechanism studies show that Alox12 inhibition does not affect activities of essential signaling pathways involved in maintaining stem cell function, such as Wnt, p53, and bone morphogenetic protein (BMP). In contrast, we show that Alox12 inhibition disrupts nicotinamide adenine dinucleotide phosphate (NADPH) homeostasis and induces oxidative stress and damage in CML HSPCs and committed cells.

Conclusion

Alox12-12-HETE axis is a specific and critical regulator of BP-CML HSPCs functions. Pharmacological inhibition of Alox12 may be useful in BP-CML.

Small Molecule Wnt Pathway Modulators from Natural Sources: History, State of the Art and Perspectives

The Wnt signaling is one of the major pathways known to regulate embryonic development, tissue renewal and regeneration in multicellular organisms. Dysregulations of the pathway are a common cause of several types of cancer and other diseases, such as osteoporosis and rheumatoid arthritis. This makes Wnt signaling an important therapeutic target. Small molecule activators and inhibitors of signaling pathways are important biomedical tools which allow one to harness signaling processes in the organism for therapeutic purposes in affordable and specific ways. Natural products are a well known source of biologically active small molecules with therapeutic potential. In this article, we provide an up-to-date overview of existing small molecule modulators of the Wnt pathway derived from natural products. In the first part of the review, we focus on Wnt pathway activators, which can be used for regenerative therapy in various tissues such as skin, bone, cartilage and the nervous system. The second part describes inhibitors of the pathway, which are desired agents for targeted therapies against different cancers. In each part, we pay specific attention to the mechanisms of action of the natural products, to the models on which they were investigated, and to the potential of different taxa to yield bioactive molecules capable of regulating the Wnt signaling.

Anisomycin inhibits angiogenesis in ovarian cancer by attenuating the molecular sponge effect of the lncRNA‑Meg3/miR‑421/PDGFRA axis

Angiogenesis has an important role in tumour cell growth and metastasis. Anisomycin has been shown to inhibit tumour cell growth. However, whether anisomycin can inhibit angiogenesis of tumours has not been reported. The present study demonstrated that there was a positive correlation between tumour angiogenesis and the number of CD44+/CD133+ serous human ovarian cancer stem cells (HuOCSCs). Subsequently, it was confirmed that anisomycin significantly inhibited the proliferation, invasion, tumorigenic ability and tumour angiogenesis of HuOCSCs. Gene expression profiling by cDNA microarrays revealed that the expression levels of vascular endothelial cell markers, platelet‑derived growth factors, Notch pathway components and 27 tumour angiogenesis‑related genes were significantly decreased in the anisomycin‑treated group compared with the control group. Further experiments demonstrated that the expression levels of endogenous long non‑coding RNA (lncRNA) maternally expressed 3 (Meg3) were significantly decreased in anisomycin‑treated HuOCSCs, whereas the expression levels of microRNA (miR)‑421 were significantly increased. The results of luciferase reporter assays indicated that, when miR‑421 was overexpressed in cells, the luciferase activities of wild‑type platelet derived growth factor receptor α (PDGFRA) 3' untranslated region and Meg3 reporter plasmids were significantly decreased. Overexpression of miR‑421 in HuOCSCs significantly enhanced the anisomycin‑mediated inhibition of HuOCSC proliferation. Taken together, the present results demonstrated that anisomycin inhibited the activation downstream of the Notch1 pathway by attenuating the molecular sponge effect of the lncRNA‑Meg3/miR‑421/PDGFRA axis, ultimately inhibiting angiogenesis, proliferation and invasion in ovarian cancer cells.

Cancer cells stemness: A doorstep to targeted therapy

Recent advances in research on cancer have led to understand the pathogenesis of cancer and development of new anticancer drugs. Despite of these advancements, many tumors have been found to recur, undergo metastasis and develop resistance to therapy. Accumulated evidences suggest that small population of cancer cells known as cancer stem cells (CSC) are responsible for reconstitution and propagation of the disease. CSCs possess the ability to self-renew, differentiate and proliferate like normal stem cells. CSCs also appear to have resistance to anti-cancer therapies and subsequent relapse. The underlying stemness properties of the CSCs are reliant on multiple molecular targets such as signaling pathways, cell surface molecules, tumor microenvironment, apoptotic pathways, microRNA, stem cell differentiation, and drug resistance markers. Thus an effective therapeutic strategy relies on targeting CSCs to overcome the possible tumor relapse and chemoresistance. The targeted inhibition of these stem cell biomarkers is one of the promising approaches to eliminate cancer stemness. This review article summarizes possible targets of cancer cell stemness for the complete treatment of cancer.