A nutrigenetic approach for investigating the chemopreventive effects of black raspberries during the development of preneoplastic esophagi in rats

Chemopreventive Properties of Black Raspberries and Strawberries in Esophageal Cancer Review

Esophageal cancer is one of the most fetal malignancies in the world. Esophageal squamous cell carcinoma (SCC) and esophageal adenocarcinoma (AC) are two main types of esophageal cancer and each with distinct epidemiological, etiological and histopathological characteristics. The continued global prevalence of tobacco use and alcohol consumption, coupled with limited intake of fresh fruits and vegetables, ensures that esophageal cancer will remain one of the major health threats. In addition to promoting quitting smoking and alcohol abuse, one of the strategies of cancer prevention is to identify foods, food components, or dietary patterns that can prevent or delay the onset of esophageal cancer. A food-based approach has the advantage of a complex of mixtures of bioactive components simultaneously targeting multiple processes in carcinogenesis. We have employed a preclinical rodent model of esophageal SCC to assess the effects of black raspberries (BRB) and strawberries. Our investigations demonstrate that BRB and strawberries are potent inhibitors of esophageal cancer. To prepare for this review, a literature search was performed to screen BRB and strawberries against esophageal cancer using electronic databases from PubMed, Science Direct and Google Scholar. Search was conducted covering the period from January 2000 to June 2022. Our present review has provided a systematic review about chemopreventive effects of BRB and strawberries in esophageal cancer by collecting and compiling diverse research findings from the above sources. In this review, we discussed the anti-tumor potentials of BRB and strawberries in esophageal SCC and esophageal AC separately. For each cancer type, we discuss animal models and research findings from both animal bioassays and human clinical studies. We also discuss the potential mechanisms of action of berries and their key bioactive components.

Black raspberries suppress pancreatic cancer through modulation of NKp46+, CD8+, and CD11b+ immune cells

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with a low survival rate (9%). Epidemiologic studies show that healthy dietary patterns enriched of fruits and vegetables lower the risk of PDAC. We previously showed that supplementing black raspberries (BRBs) to patients with colorectal cancer increased tumor-infiltrating NK cells and their cytotoxicity. We aimed to determine whether BRBs combat PDAC by modulating cancer immunity. NOD.SCID mice lacking T and B cells were injected with human Panc-1-Luc cells orthotopically, and immunocompetent Kras ^LSL.G12D/+ -Trp53 ^LSL.R172H/+ -Pdx-1-Cre mice were fed BRBs. Peripheral blood mononuclear cells (PBMCs) from PDAC patients were treated with butyrate, a microbial metabolite of BRBs. The absence of T and B cells did not dampen BRBs' anti-tumor effects in the NOD.SCID mice. In the Kras ^LSL.G12D/+ -Trp53 ^LSL.R172H/+ -Pdx-1-Cre mice, BRBs significantly prolonged survival (189 days versus 154 days). In both models, BRBs decreased tumor-infiltrating CD11b⁺ cells and the expression of IL-1β, sEH, and Ki67. BRBs also increased tumor-infiltrating NKp46⁺ cells and the expression of CD107a, a functional marker of cytolytic NK and CD8⁺ T cells. In Kras ^LSL.G12D/+ -Trp53 ^LSL.R172H/+ -Pdx-1-Cre mice, tumor infiltration of CD8⁺ T cells was increased by BRBs. Further using the PBMCs from PDAC patients, we show that butyrate decreased the population of myeloid-derived suppressor cells (MDSCs). Butyrate also reversed CD11b⁺ cell-mediated suppression on CD8⁺ T cells. Interestingly, there is a negative association between MDSC changes and patients' survival, suggesting that the more decrease in MDSC population induced by butyrate treatment, the longer the patient had survived. Our study suggests the immune-modulating potentials of BRBs in PDAC.

Ornithine decarboxylase inhibition downregulates multiple pathways involved in the formation of precancerous lesions of esophageal squamous cell cancer

The high incidence and mortality of esophageal squamous cell cancer (ESCC) is a major health problem worldwide. Precancerous lesions of ESCC may either progress to cancer or revert to normal epithelium with appropriate interventions; the bidirectional instability of the precancerous lesions of ESCC provides opportunities for intervention. Reports suggest that the upregulation of ornithine decarboxylase (ODC) is closely related to carcinogenesis. In this study, we investigated whether ODC may act as a target for chemoprevention in ESCC. Immunohistochemistry (IHC) assays indicate that ODC expression is higher in esophageal precancerous lesions compared with normal tissue controls. Its overexpression promotes cell proliferation and transformation of normal esophageal epithelial cells, and its activity is increased after N-nitrosomethylbenzylamine (NMBA) induction in Shantou human embryonic esophageal cell line (SHEE) and human immortalized cells (Het1A) cells. In addition, p38 α, extracellular regulated kinase (ERK1/2) in the mitogen-activated protein kinase pathway and protein kinase B (AKT)/mammalian target of rapamycin (mTOR)/ribosomal protein S6 kinase (p70S6K) pathways are activated in response to NMBA treatment. Difluoromethylornithine (DFMO) is an ODC inhibitor, which inhibits NMBA-induced activation of p38 α, ERK1/2 and AKT/mTOR/p70S6K pathways; this has been verified by Western blotting. DFMO was also found to suppress the development of esophageal precancerous lesions in an NMBA-induced rat model; IHC demonstrated p38 α, ERK1/2, and AKT/mTOR/p70S6K pathways to be downregulated in these rats. These findings indicate the mechanisms by which ODC inhibition suppresses the development of esophageal precancerous lesions by downregulating p38 α, ERK1/2, and AKT/mTOR/p70S6k signaling pathways, ODC may be a potential target for chemoprevention in ESCC.

Isolation of strawberry anthocyanin-rich fractions and their mechanisms of action against murine breast cancer cell lines

The aim of this study was the evaluation of the effects of strawberry anthocyanin extract treatment on two in vitro models of murine breast cancer cell lines, in an attempt to detect a specific pathway (AMP-activated protein kinase or AMPK) through which strawberries exert their anticancer activity. The anticancer activity of purified anthocyanin extracts from an Alba cultivar on two murine cancer cell lines, N202/1A (with high levels of the HER2/neu oncogene) and N202/1E (with low levels of the HER2/neu oncogene), was evaluated after 48 and 72 h of treatment. The cell viability and apoptosis, intracellular ROS rates, and cell oxidative damage were assessed. Western blot assays were performed to analyze the expression of several proteins related to apoptosis, autophagy, metastasis, the oxidative status, mitochondrial functionality, and the AMPK pathway. This study demonstrated that the anthocyanin extract of Alba strawberry shows an antiproliferative effect on cancer cells, through the induction of apoptosis and oxidative stress, by stimulating different molecular pathways. This study is one of the first studies that have tried to deepen the understanding of a candidate pathway for the explanation of the effects of strawberry on cancer cells. A relationship between the AMPK pathway and the anticancer effects of strawberries was demonstrated.