Starvation based differential chemotherapy: a novel approach for cancer treatment

Bacteria colonization in tumor microenvironment creates a favorable niche for immunogenic chemotherapy

The tumor microenvironment (TME) presents differential selective pressure (DSP) that favors the growth of cancer cells, and monovalent therapy is often inadequate in reversing the cancer cell dominance in the TME. In this work, we introduce bacteria as a foreign species to the TME and explore combinatorial treatment strategies to alter DSP for tumor eradication. We show that cancer-selective chemotherapeutic agents and fasting can provide a strong selection pressure against tumor growth in the presence of bacteria. Moreover, we show that an immunogenic drug (oxaliplatin), but not a non-immunogenic one (5-FU), synergizes with the bacteria to activate both the innate and adaptive immunity in the TME, resulting in complete tumor remission and a sustained anti-tumor immunological memory in mice. The combination of oxaliplatin and bacteria greatly enhances the co-stimulatory and antigen-presenting molecules on antigen-presenting cells, which in turn bridge the cytotoxic T cells for cancer-cell killing. Our findings indicate that rational combination of bacterial therapy and immunogenic chemotherapy can promote anticancer immunity against the immunosuppressive TME.

[LncRNA SOX2OT enhances 5-fluorouracil resistance of cholangiocarcinoma cells by promoting autophagy via up-regulating SIRT1 expression]

OBJECTIVE

To investigate the role of SIRT1/autophagy pathway in mediating the regulatory effect of lncRNA SOX2OT on 5-fluorouracil (5-FU) resistance in cholangiocarcinoma cells.

METHODS

HCCC-9810 cells were used to construct a 5-FU-resistant cell model (HCCC-9810/5-FU cells), and the expression levels of lncRNA SOX2OT and SIRT1 mRNA and the protein expressions of SIRT1, Beclin1, LC3 and P62 were detected with qRT-PCR and Western blotting. The effects of transfection with a SOX2OT mimic on drug resistance and cell migration of HCCC-9810/5-FU cells were detected using CCK-8 assay and wound healing assay, and the changes in expressions of SOX2OT, SIRT1, Beclin1, LC3 and P62 were detected. Rescue experiment was performed by co-transfection of HCCC-9810/5-FU cells with both a SOX2OT-overexpressing plasmid and si-SIRT1 to confirm the role of SIRT1 in SOX2OT-mediated regulation of 5-FU resistance. A RNA pulldown assay was used to verify the targeted binding between SOX2OT and SIRT1.

RESULTS

The proliferation of HCCC-9810 cells was significantly inhibited after treatment with different concentrations of 5-FU (P < 0.05). The 5-FU-resistant cells showed significantly increased protein expressions of SIRT1, Beclin1 and p62, an increased LC3 Ⅱ/LC3 Ⅰ ratio, and enhanced expressions of SIRT1 mRNA and SOX2OT (P < 0.05). Transfection of the resistant cells with SOX2OT mimic significantly enhanced cell migration and increased the protein expressions of SIRT1, Beclin1 and p62, the LC3Ⅱ/LC3Ⅰ ratio, and expression levels of SIRT1 mRNA and SOX2OT (P < 0.05), and these changes were obviously attenuated by SIRT1 knockdown, which also resulted in lowered 5-FU resistance of the cells without significantly affecting the expression level of SOX2OT (P > 0.05). RNA pulldown assay suggested that SOX2OT could directly bind to SIRT1.

CONCLUSION

LncRNA SOX2OT enhances 5-FU resistance in HCCC-9810 cells by promoting autophagy through up-regulating SIRT1 expression.

Impact of Fasting on Patients With Cancer: An Integrative Review

Background

Patients with cancer often pursue nutrition as an avenue to positively impact their care management and disease outcomes. Nutritional interventions are increasing in popularity, especially intermittent fasting as an adjunct to chemotherapy. However, limited research is available on the impact of intermittent fasting on patients with cancer.

Methods

A comprehensive literature search was conducted using Ovid MEDLINE, Ovid EMBASE, and CINAHL databases.

Results

514 articles were identified from the three databases. Seven studies remained after applying inclusion and exclusion criteria. The seven studies included in this review examined fasting compliance, malnutrition, therapy side effects, endocrine parameters, quality of life measures, and cancer outcomes. Data suggest overall good compliance, no malnutrition, minimal side effects, a trend toward improved endocrine parameters, unchanged quality of life (QOL), and mixed results for cancer outcomes.

Conclusion

Intermittent fasting as an adjunct to chemotherapy in normal-weight patients with cancer has potential as a safe, tolerable, and feasible nutritional intervention that could positively impact treatment outcomes and QOL. Large-scale randomized controlled trials are needed to validate these findings and determine what future role intermittent fasting may play in cancer management.

Cancer—A Pragmatic Switch to Combat Metabolic Syndrome?

Both cancer and metabolic disease have become the prevalent health risks in modern societies worldwide. Cancer is a complex set of illnesses with many definitions. About 15% of cancers are caused by infections, and 10% carry a hereditary burden. The remaining 70%–75% cancers are associated with a variety of processes, often associated with metabolic syndrome and chronic inflammation. This review examines the role of metabolic dysfunction and chronic inflammation in cancer development. I propose a novel concept of a switch, in which our intelligent body uses its sophisticated set of subsystems and sensors to pragmatically anticipate and combat metabolic dysfunction as its’ most direct and dire threat first, while temporarily accepting cancer as a state that in any other circumstances would be considered detrimental, and utilizing cancer as an additional tool to lower glucose levels. Once metabolic dysfunction has been resolved this switch is reversed, and cancer growth will be impaired.

Folic Acid-Functionalized Carbon Dot-Enabled Starvation Therapy in Synergism with Paclitaxel against Breast Cancer

Glucose oxidase (GOx)-induced cancer starvation has recently emerged for halting the abnormal proliferation of triple-negative breast cancer (TNBC). However, monotherapy with GOx or a conventional chemotherapeutic displays suboptimal efficacy in eliminating tumors and poses impending risks to healthy tissues. To augment therapeutic efficacy and tumor selectivity, folic acid (FA)-functionalized carbon dots (CDs) embedded with GOx and paclitaxel (PTX) [FA-CD-(PTX-GOx)] was developed that showed the efficient killing of TNBC, MDA-MB-468 cells over noncancerous HEK 293 cells through synergistic effects of cancer starvation-induced oxidative stress and chemotherapy. The cargo-laden FA-CD complex resulted in a 4-8 fold increase in cancer cell death at 60 μg/mL when compared to standalone therapy with the native compounds and individually loaded cargo on FA-CD. This improved cancer cell killing efficacy of the FA-CD-(PTX-GOx) complex could be endorsed by folate receptor (FR)-mediated target-specific cellular internalization of the FA-CD complex. The antitumorigenic efficacy of the FA-CD-(PTX-GOx) complex was further validated in a three-dimensional (3D) breast tumor spheroid model. A significant 4.5-fold reduction in spheroid dimension along with antiproliferation was observed with time up to 72 h following exposure to the FA-CD-(PTX-GOx) complex. This antitumorigenic potential of FA-CD-(PTX-GOx) could be attributed to the enhanced intratumoral reactive oxygen species generation following glucose depletion by GOx that has been facilitated by the chemotherapeutic efficacy of PTX resulting in the efficient killing of cancer cells. The present study provides a novel strategy of FR-mediated fluorescent CD-enabled combined formulation of GOx and PTX for the target-specific superior killing of TNBC cells in the synergism of glucose starvation with chemotherapy.

Effects of Fasting on Chemotherapy Treatment Response: A Systematic Review of Current Evidence and Suggestions for the Design of Future Clinical Trials

Fasting associated with chemotherapy could improve the efficacy of anticancer treatments without increasing their adverse effects. We conducted a systematic review following the PRISMA Statement to summarize the evidence on the effects of fasting on treatment response of adults undergoing chemotherapy and make suggestions for the design of future clinical trials The search was performed on CENTRAL, PubMed/MEDLINE, LILACS and Embase. Randomized and non-randomized clinical trials evaluating the effects of fasting (above 12 h, at anytime) on treatment response of adult cancer patients undergoing chemotherapy were included. The risk of bias assessment was conducted in accordance with the Cochrane Handbook. Literature search retrieved 1393 citations and three studies were included in the review. All studies had as an intervention fasting of at least 24 h, before chemotherapy. Two studies showed that immediately after chemotherapy, damage to healthy cells was increased, however after 48 and 72 h, of fasting there was a decrease on damage magnitude. There was no difference in chemotherapy-related adverse events between intervention and control groups. All studies presented two or more criteria with a high risk of bias. Fasting of at least 24 h, appears to be safe and showed some beneficial effects on chemotherapy toxicity, that could be further investigated, however studies presented heterogeneous samples and protocols. We highlight the need and provide recommendations for well-designed randomized clinical trials that evaluate the effect of fasting on chemotherapy-related adverse events. This systematic review was registered on PROSPERO as CRD42019120071.

Intermittent fasting in the prevention and treatment of cancer

Chronic caloric restriction (CR) has powerful anticarcinogenic actions in both preclinical and clinical studies but may be difficult to sustain. As an alternative to CR, there has been growing interest in intermittent fasting (IF) in both the scientific and lay community as a result of promising study results, mainly in experimental animal models. According to a survey by the International Food Information Council Foundation, IF has become the most popular diet in the last year, and patients with cancer are seeking advice from oncologists about its beneficial effects for cancer prevention and treatment. However, as discussed in this review, results from IF studies in rodents are controversial and suggest potential detrimental effects in certain oncologic conditions. The effects of IF on human cancer incidence and prognosis remain unknown because of a lack of high-quality randomized clinical trials. Preliminary studies suggest that prolonged fasting in some patients who have cancer is safe and potentially capable of decreasing chemotherapy-related toxicity and tumor growth. However, because additional trials are needed to elucidate the risks and benefits of fasting for patients with cancer, the authors would not currently recommend patients undergoing active cancer treatment partake in IF outside the context of a clinical trial. IF may be considered in adults seeking cancer-prevention benefits through means of weight management, but whether IF itself affects cancer-related metabolic and molecular pathways remains unanswered.

How Far Are We from Prescribing Fasting as Anticancer Medicine?

(1) Background: the present review provides a comprehensive and up-to date overview of the potential exploitation of fasting as an anticancer strategy. The rationale for this concept is that fasting elicits a differential stress response in the setting of unfavorable conditions, empowering the survival of normal cells, while killing cancer cells. (2) Methods: the present narrative review presents the basic aspects of the hormonal, molecular, and cellular response to fasting, focusing on the interrelationship of fasting with oxidative stress. It also presents nonclinical and clinical evidence concerning the implementation of fasting as adjuvant to chemotherapy, highlighting current challenges and future perspectives. (3) Results: there is ample nonclinical evidence indicating that fasting can mitigate the toxicity of chemotherapy and/or increase the efficacy of chemotherapy. The relevant clinical research is encouraging, albeit still in its infancy. The path forward for implementing fasting in oncology is a personalized approach, entailing counteraction of current challenges, including: (i) patient selection; (ii) fasting patterns; (iii) timeline of fasting and refeeding; (iv) validation of biomarkers for assessment of fasting; and (v) establishment of protocols for patients’ monitoring. (4) Conclusion: prescribing fasting as anticancer medicine may not be far away if large randomized clinical trials consolidate its safety and efficacy.

Use of Small-molecule Inhibitory Compound of PERK-dependent Signaling Pathway as a Promising Target-based Therapy for Colorectal Cancer

BACKGROUND

Colorectal cancer constitutes one of the most common cancer with a high mortality rate. The newest data has reported that activation of the pro-apoptotic PERK-dependent unfolded protein response signaling pathway by small-molecule inhibitors may constitute an innovative anti-cancer treatment strategy.

OBJECTIVE

In the presented study, we evaluated the effectiveness of the PERK-dependent unfolded protein response signaling pathway small-molecule inhibitor 42215 both on HT-29 human colon adenocarcinoma and CCD 841 CoN normal human colon epithelial cell lines.

METHODS

Cytotoxicity of the PERK inhibitor was evaluated by the resazurin-based and lactate dehydrogenase (LDH) tests. Apoptotic cell death was measured by flow cytometry using the FITCconjugated Annexin V to indicate apoptosis and propidium iodide to indicate necrosis as well as by colorimetric caspase-3 assay. The effect of tested PERK inhibitor on cell cycle progression was measured by flow cytometry using the propidium iodide staining. The level of the phosphorylated form of the eukaryotic initiation factor 2 alpha was detected by the Western blot technique.

RESULTS

Obtained results showed that investigated PERK inhibitor is selective only toward cancer cells, since inhibited their viability in a dose- and time-dependent manner and induced their apoptosis and G2/M cell cycle arrest. Furthermore, 42215 PERK inhibitor evoked significant inhibition of eIF2α phosphorylation within HT-29 cancer cells.

CONCLUSION

Highly-selective PERK inhibitors may provide a ground-breaking, anti-cancer treatment strategy via activation of the pro-apoptotic branch of the PERK-dependent unfolded protein response signaling pathway.

A review of nutrition and dietary interventions in oncology

The complex cellular mechanisms and inter-related pathways of cancer proliferation, evasion, and metastasis remain an emerging field of research. Over the last several decades, nutritional research has prominent role in identifying emerging adjuvant therapies in our fight against cancer. Nutritional and dietary interventions are being explored to improve the morbidity and mortality for cancer patients worldwide. In this review, we examine several dietary interventions and their proposed mechanisms against cancer as well as identifying limitations in the currently available literature. This review provides a comprehensive review of the cancer metabolism, dietary interventions used during cancer treatment, anti metabolic drugs, and their impact on nutritional deficiencies along with a critical review of the following diets: caloric restriction, intermittent fasting, ketogenic diet, Mediterranean diet, Japanese diet, and vegan diet.

Effects of Hyperbaric Oxygen on T helper 17/regulatory T Polarization in Antigen and Collagen-induced Arthritis: Hypoxia-inducible Factor-1α as a Target

Objectives

We sought to investigate and prove the effect of hyperbaric oxygen therapy (HBOT) on T helper 17 (Th17)/regulatory T (Treg) cell polarization through changes in the expression of hypoxia-inducible factor-1 alpha (HIF-1α) in rheumatoid arthritis (RA) animal model.

Methods

We used antigen and collagen-induced arthritis (ACIA) as a RA animal model. Sixteen male BALB/c models of ACIA mice were divided into two groups, the non-HBOT group as the control group and the HBOT group as the treatment group. Expression of HIF-1α, Th17 anti-cluster differentiation 196 (CD196), and Treg anti-interleukine 2 receptor β-chain cells (IL-2Rβ) in tissue from the left knee joint tissue were determined histologically. Oxidative stress and systemic inflammation were assessed by levels of superoxide dismutase (SOD), interleukin 17a (IL-17a), C-reactive protein (CRP), and rheumatoid factor (RF) using the enzyme-linked immune-sorbent assay. The degree of arthritis was assessed by clinical scoring of paw swelling and the diameter of paw swelling.

Results

We found a significant decrease (p < 0.050) in the expression of HIF-1α, Th17 (CD196), IL-17a, RF levels, and the clinical scores and the diameter of paw swelling when comparing both groups. There was no significant decrease in the level of CRP in the treatment group compared to the control group. The expression of Treg (IL-2Rβ) increased significantly (p < 0.050) and the level of SOD increased but not significantly (p > 0.050) in the treatment group compared to the control group.

Conclusions

HBOT has effects on the polarization of Th17 to Treg through a decrease in expression of HIF-1α in mice with ACIA. HBOT is recommended for use as a support therapy for RA in combination with drug therapy.

Dichloroacetate enhances the antitumor efficacy of chemotherapeutic agents via inhibiting autophagy in non-small-cell lung cancer

Background

Chemotherapy is still the primary adjuvant strategy of cancer therapy; however, the emergence of multi-drug resistance has been a cause for concern. Autophagy has been demonstrated to have a protective role against chemotherapeutic drugs in cancer cells, and autophagy inhibition is generally considered to be a promising therapeutic strategy. However, the paucity of effective and specific autophagy inhibitors limits its application.

Purpose

The objective of this study was to explore the effect of DCA, small molecular anti-tumor agent, on the autophagy regulation and chemosensitization in NSCLC cells.

Methods

We investigated the autophagy regulation of dichloroacetate (DCA) by laser confocal microscopy and western blotting in A549 and H1975 cell lines. The MTT assay and flow cytometry was performed for explore the chemosensitization effectiveness of DCA. The results were verified with subcutaneous tumor model in nude mice and the immunohistochemistry was applied for assessing the level of cell apoptosis and autophagy in vivo post treatment.

Results

We found that DCA, which exhibited antitumor properties in various carcinoma models, induced apoptosis of non-small cell lung cancer cells (NSCLC) by inhibiting cancer cell autophagy. Furthermore, Perifosine, an AKT inhibitor, can greatly weaken the capacity of inducing apoptosis by DCA. The results indicate that the AKT-mTOR pathway, a main negative regulator of autophagy, is involved in the DCA-induced inhibition of autophagy. Then, we detected the effectiveness of autophagy inhibition by DCA. When used in co-treatment with the chemotherapeutic drug paclitaxel (PTX), DCA markedly decreased cell autophagy, enhanced apoptosis and inhibited proliferation in A549 and H1975 cells. The results of the xenograft experiment demonstrate that co-treatment of PTX and DCA can significantly decrease cell proliferation in vivo and prolong the survival of mice.

Conclusion

Our results suggest that DCA can inhibit cell autophagy induced by chemotherapeutics, providing a new avenue for cancer chemotherapy sensitization.

Starvation-Induced Stress Response Is Critically Impacted by Ceramide Levels in Caenorhabditis elegans

Our understanding of the cellular mechanisms by which animals regulate their response to starvation is limited, despite the strong relevance of the problem to major human health issues. The L1 diapause of Caenorhabditis elegans, where first-stage larvae arrest in response to a food-less environment, is an excellent system to study this mechanism. We found, through genetic manipulation and lipid analysis, that biosynthesis of ceramide, particularly those with longer fatty acid side chains, critically impacts animal survival during L1 diapause. Genetic interaction analysis suggests that ceramide may act in both insulin-IGF-1 signaling (IIS)-dependent and IIS-independent pathways to affect starvation survival. Genetic and expression analyses indicate that ceramide is required for maintaining the proper expression of previously characterized starvation-responsive genes, genes that are regulated by the IIS pathway and tumor suppressor Rb, and genes responsive to pathogen. These findings provide an important insight into the roles of sphingolipid metabolism, not only in starvation response, but also in aging and food-response-related human health problems.

The Histone Deacetylase Gene Rpd3 Is Required for Starvation Stress Resistance

Epigenetic regulation in starvation is important but not fully understood yet. Here we identified the Rpd3 gene, a Drosophila homolog of histone deacetylase 1, as a critical epigenetic regulator for acquiring starvation stress resistance. Immunostaining analyses of Drosophila fat body revealed that the subcellular localization and levels of Rpd3 dynamically changed responding to starvation stress. In response to starvation stress, the level of Rpd3 rapidly increased, and it accumulated in the nucleolus in what appeared to be foci. These observations suggest that Rpd3 plays a role in regulation of rRNA synthesis in the nucleolus. The RT-qPCR and ChIP-qPCR analyses clarified that Rpd3 binds to the genomic region containing the rRNA promoters and activates rRNA synthesis in response to starvation stress. Polysome analyses revealed that the amount of polysomes was decreased in Rpd3 knockdown flies under starvation stress compared with the control flies. Since the autophagy-related proteins are known to be starvation stress tolerance proteins, we examined autophagy activity, and it was reduced in Rpd3 knockdown flies. Taken together, we conclude that Rpd3 accumulates in the nucleolus in the early stage of starvation, upregulates rRNA synthesis, maintains the polysome amount for translation, and finally increases stress tolerance proteins, such as autophagy-related proteins, to acquire starvation stress resistance.

Autophagic Cell Death by Poncirus trifoliata Rafin., a Traditional Oriental Medicine, in Human Oral Cancer HSC-4 Cells

Poncirus trifoliata Rafin. has long been used as anti-inflammatory and antiallergic agent to treat gastrointestinal disorders and pulmonary diseases such as indigestion, constipation, chest fullness, chest pain, bronchitis, and sputum in Korea. P. trifoliata extract has recently been reported to possess anticancer properties; however, its mechanisms of action remain unclear. In this study, its antiproliferative effects and possible mechanisms were investigated in HSC-4 cells. The methanol extract of P. trifoliata (MEPT) significantly decreased the proliferation of HSC-4 cells (inhibitory concentration (IC)₅₀ = 142.7 μg/mL) in a dose-dependent manner. While there were no significant changes observed upon cell cycle analysis and ANNEXIN V and 7-AAD double staining in the MEPT-treated groups, the intensity of acidic vesicular organelle (AVO) staining and microtubule-associated protein 1 light chain (LC) 3-II protein expression increased in response to MEPT treatment. Furthermore, 3-methyladenine (3-MA, autophagy inhibitor) effectively blocked the MEPT-induced cytotoxicity of HSC-4 cells and triggered the activation of p38 and extracellular signal-regulated kinases (ERK) proteins. Taken together, our results indicate that MEPT is a potent autophagy agonist in oral cancer cells with antitumor therapeutic potential that acts through the mitogen-activated protein kinase (MAPK) pathway.

Capsaicin Enhances the Drug Sensitivity of Cholangiocarcinoma through the Inhibition of Chemotherapeutic-Induced Autophagy

Cholangiocarcinoma (CCA), a devastating cancer with a poor prognosis, is resistant to the currently available chemotherapeutic agents. Capsaicin, the major pungent ingredient found in hot red chili peppers of the genus Capsicum, suppresses the growth of several malignant cell lines. Our aims were to investigate the role and mechanism of capsaicin with respect to the sensitivity of CCA cells to chemotherapeutic agents. The effect of capsaicin on CCA tumor sensitivity to 5-fluorouracil (5-FU) was assessed in vitro in CCA cells and in vivo in a xenograft model. The drug sensitivity of QBC939 to 5-FU was significantly enhanced by capsaicin compared with either agent alone. In addition, the combination of capsaicin with 5-FU was synergistic, with a combination index (CI) < 1, and the combined treatment also suppressed tumor growth in the CCA xenograft to a greater extent than 5-FU alone. Further investigation revealed that the autophagy induced by 5-FU was inhibited by capsaicin. Moreover, the decrease in AKT and S6 phosphorylation induced by 5-FU was effectively reversed by capsaicin, indicating that capsaicin inhibits 5-FU-induced autophagy by activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway in CCA cells. Taken together, these results demonstrate that capsaicin may be a useful adjunct therapy to improve chemosensitivity in CCA. This effect likely occurs via PI3K/AKT/mTOR pathway activation, suggesting a promising strategy for the development of combination drugs for CCA.