Evaluation of aflibercept in the treatment of metastatic colorectal cancer

Phytochemical Regulation of RNA in Treating Inflammatory Bowel Disease and Colon Cancer: Inspirations from Cell and Animal Studies

Recent studies suggest an important role for RNA, especially noncoding RNA, in inflammatory bowel disease (IBD) and colon cancer. Drug development based on regulating RNA rather than protein is a promising new area. Phytochemicals are naturally occurring plant-derived compounds with chemical diversity, biologic activity, easy availability, and low toxicity. Many phytochemicals have been shown to exert protective effects on IBD and colon cancer through modulation of RNAs. The aim of this study was to summarize the advancements of phytochemicals in regulating RNA for the treatment of IBD and colon cancer. This review involves many phytochemicals, including polyphenols, flavones, and alkaloids, which can influence various types of RNAs, including microRNA, long noncoding RNA, as well as messenger RNA, by influencing a variety of upstream molecules or regulating epigenetic processes. The limitation for many current studies is that the specific mechanisms of phytochemicals regulating RNA have not been fully uncovered. Accompanied by more identified functions of RNAs, especially noncoding RNA functions, the screening of RNA-regulating phytochemicals has presented challenges as well as opportunities for the prevention and treatment of IBD and colon cancer. SIGNIFICANCE STATEMENT: Noncoding RNAs, which constitute the majority of the human transcriptional genome, play a key role in the disease state and are considered as important therapeutic targets in inflammatory bowel disease (IBD) and colon cancer. Recent studies have shown that phytochemicals regulate the expression of many noncoding RNAs involved in IBD and colon cancer. Therefore, identifying the specific molecular mechanism of phytochemicals regulating noncoding RNA in disease models may result in novel and effective therapeutic opportunities.

VEGFR-1 Regulates EGF-R to Promote Proliferation in Colon Cancer Cells

The relationship between epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) pathways in tumor growth is well established. EGF induces VEGF production in cancer cells, and the paracrine VEGF activates vascular endothelial cells to promote tumor angiogenesis and thus supports tumor cell growth in an angiogenesis-dependent manner. In this study, we found angiogenesis-independent novel crosstalk between the VEGF and the EGF pathways in the regulation of colon cancer cell proliferation. Stimulation of colon cancer cells with VEGF-A and placental growth factor (PlGF) activated VEGF receptor-1 (VEGFR-1) and increased proliferation activity in an autocrine EGF/EGF receptor (EGF-R)-dependent manner. Mechanistically, VEGFR-1 interacted with and stabilized EGF-R, leading to increased EGF-R protein levels and prolonged its expression on cell surface plasma membrane. In contrast, VEGFR-1 blockade by a neutralizing antibody and an antagonistic peptide of VEGFR-1 suppressed the complex formation of VEGFR-1 and EGF-R and decreased EGF-R expression via a lysosome-dependent pathway, resulting in the suppression of proliferation activity. Our results indicated that VEGFR-1 regulated EGF-R expression to promote proliferation activity in a cell-autonomous-dependent manner.

Antiproliferation effect of evodiamine in human colon cancer cells is associated with IGF-1/HIF-1α downregulation

Colon cancer is one of the most common malignancies. Although the current treatment regimes for colon cancer have been well-developed in the past decades, the prognosis remains still undesirable. It is still urgent to explore new treatment strategies for colon cancer. Natural products is one of the most useful sources for anticancer agents, although some of them have serious side-effects. Evodiamine (Evo) is an quinolone alkaloid from the traditional herb medicine Evodia rutaecarpa. In the present study, we investigated the anticancer effect of Evo in human colon cancer cells. We found that Evo exhibits prominent antiproliferation and apoptosis inducing effects in LoVo cells. Evo leads to apparent downregulation of HIF-1α either in vitro or in vivo; exogenous expression of HIF-1α can attenuate the antiproliferation effect of Evo in LoVo cells, while HIF-1α knockdown potentiates this effect greatly. Further analysis indicated that Evo can also inhibit the phosphorylation of Akt1/2/3 and decrease greatly the expression of IGF-1. Thus, our findings strongly suggested that the anticancer effect of Evo in human colon cancer may be partly mediated by downregulating HIF-1α expression, which is initiated by inactivating PI3K/Akt signaling transduction though decreasing the expression of IGF-1 in colon cancer cells. Therefore, Evo may be used alone or in combination as a potential anticancer agent for colon cancer treatment.

Cellular signaling pathways implicated in metastasis of colorectal cancer and the associated targeted agents

Colorectal cancer (CRC) is the third leading cancer worldwide and CRC-related death is mainly attributed to metastasis. Many cellular signaling pathways have been demonstrated to be aberrant in colorectal tumors, and some of them lead to the acquisition of malignant phenotypes. Therefore, the evaluation of signaling pathways implicated in CRC metastasis is urgent for further understanding of CRC progression and pharmacotherapy. This review focuses on several novel cellular signaling pathways associated with CRC metastasis, including Wnt/β-catenin, p53, COX, TGF-β/Smad, NF-κB, Notch, VEGF and JAKs/STAT3 signaling pathways. Targeted agents developed based on these pathways are also briefly discussed.

Emerging antibody-based therapeutic strategies for bladder cancer: A systematic review

Bladder cancer is the most common malignancy of the urinary tract, presents the highest recurrence rate among solid tumors and is the second leading cause of death in genitourinary cancers. Despite recent advances in understanding of pathophysiology of the disease, the management of bladder cancer patients remains a clinically challenging problem. Particularly, bladder tumors invading the muscularis propria and disseminated disease are often not responsive to currently available therapeutic approaches, which include surgery and conventional chemotherapy. Antibody-based therapeutic strategies have become an established treatment option for over a decade in several types of cancer. However, bladder cancer has remained mostly an "orphan disease" regarding the introduction of these novel therapeutics, which has been translated in few improvements in patients overall survival. In order to shift this paradigm, several clinical studies involving antibody-based therapeutic strategies targeting the most prominent bladder cancer-related biomolecular pathways and immunological mediators are ongoing. This systematic review explores antibody-based therapeutics for bladder cancer undergoing clinical trial and discusses the future perspectives in this field, envisaging the development of more effective guided therapeutics.

Antiangiogenic agents in gynecological cancer: State of art and perspectives of clinical research

Vascular endothelial growth factor [VEGF] pathway, which plays a key role in angiogenesis, may be blocked by either extracellular interference with VEGF itself (bevacizumab [BEV] or aflibercept), or intracytoplasmic inhibition of VEGF receptor (pazopanib, nintedanib, cediranid, sunitinib and sorafenib). An alternative approach is represented by trebananib, a fusion protein that prevents the interaction of angiopoietin [Ang]-1 and Ang-2 with Tie2 receptor on vascular endothelium. The combination of antiangiogenic agents, especially BEV, and chemotherapy is a rational therapeutic option for primary or recurrent ovarian carcinoma. However, it will be difficult to accept that it represents the new standard treatment, until biological characterization of ovarian carcinoma has not identified subsets of tumors with different responsiveness to BEV. Anti-angiogenesis is an interesting target also for recurrent cervical or endometrial cancer, but nowadays the use of anti-angiogenic agents in these malignancies should be reserved to patients enrolled in clinical trials.

A randomized Phase II clinical study of combining panitumumab and bevacizumab, plus irinotecan, 5-fluorouracil, and leucovorin (FOLFIRI) compared with FOLFIRI alone as second-line treatment for patients with metastatic colorectal cancer and KRAS mutation

BACKGROUND

This study investigated the efficacy and safety of a new treatment strategy of combining panitumumab and bevacizumab, plus irinotecan, 5-fluorouracil, and leucovorin (FOLFIRI) versus FOLFIRI alone as second-line chemotherapy for metastatic colorectal cancer (mCRC) patients with known V-Ki-ras2 Kirsten rat sarcoma viral oncogene (KRAS) mutation status.

METHODS

Patients with mCRC who had known KRAS tumor status and unsuccessful previous oxaliplatin-based chemotherapy were included in the study. They were randomly assigned to two groups to receive panitumumab and bevacizumab plus FOLFIRI, or FOLFIRI alone. In panitumumab and bevacizumab plus FOLFIRI group, patients were given 4 mg/kg panitumumab and bevacizumab plus FOLFIRI every 2 weeks.

RESULTS

In all, 65 patients were assigned to panitumumab and bevacizumab plus FOLFIRI group, and 77 to FOLFIRI alone group. For WT KRAS patients, the median progression-free survival (PFS) was 5.7 months (95% confidence interval [CI], 2.4-7.5 months) for panitumumab and bevacizumab plus FOLFIRI and 3.8 months (95% CI, 3.0-6.7 months) for FOLFIRI alone; median overall survival (OS) was 15.2 months (95% CI, 8.9-19.7 months) for panitumumab and bevacizumab plus FOLFIRI and 11.0 months (95% CI, 8.2-15.4 months) for FOLFIRI alone. For MU KRAS patients, median PFS was 5.1 months (95% CI, 2.7-10.2 months) for panitumumab and bevacizumab plus FOLFIRI and 4.1 months (95% CI, 2.5-8.4 months) for FOLFIRI alone; median OS was 12.8 months (95% CI, 7.8-15.8 months) for panitumumab and bevacizumab plus FOLFIRI and 10.5 months (95% CI, 6.1-15.3 months) for FOLFIRI alone. Grade 3 and 4 adverse events were associated with panitumumab and bevacizumab plus FOLFIRI but tolerable among patients.

CONCLUSION

Patients with mCRC can be safely and efficiently treated with second-line chemotherapy of combining panitumumab and bevacizumab plus FOLFIRI, despite their KRAS mutation status.

Protopanaxadiol, an active ginseng metabolite, significantly enhances the effects of fluorouracil on colon cancer

In this study, we evaluated the effects of protopanaxadiol (PPD), a gut microbiome induced ginseng metabolite, in increasing the anticancer effects of a chemotherapeutic agent fluorouracil (5-FU) on colorectal cancer. An in vitro HCT-116 colorectal cancer cell proliferation test was conducted to observe the effects of PPD, 5-FU and their co-administration and the related mechanisms of action. Then, an in vivo xenografted athymic mouse model was used to confirm the in vitro data. Our results showed that the human gut microbiome converted ginsenoside compound K to PPD as a metabolite. PPD and 5-FU significantly inhibited HCT-116 cell proliferation in a concentration-dependent manner (both p < 0.01), and the effects of 5-FU were very significantly enhanced by combined treatment with PPD (p < 0.01). Cell cycle evaluation demonstrated that 5-FU markedly induced the cancer cell S phase arrest, while PPD increased arrest in G1 phase. Compared to the control, 5-FU and PPD increased apoptosis, and their co-administration significantly increased the number of apoptotic cells (p < 0.01). Using bioluminescence imaging, in vivo data revealed that 5-FU significantly reduced the tumor growth up to Day 20 (p < 0.05). PPD and 5-FU co-administration very significantly reduced the tumor size in a dose-related manner (p < 0.01 compared to the 5-FU alone). The quantification of the tumor size and weight changes for 43 days supported the in vivo imaging data. Our results demonstrated that the co-administration of PPD and 5-FU significantly inhibited the tumor growth, indicating that PPD significantly enhanced the anticancer action of 5-FU, a commonly used chemotherapeutic agent. PPD may have a clinical value in 5-FU’s cancer therapeutics.