Anti-Cancer Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Anti-Cancer Agents) - Volume 13, Issue 6, 2013

Multidisciplinary team (MDT) is of paramount importance in the approach to patients with head and neck cancer. Its aim is to provide the best diagnostic work-up, tumor staging, and treatment. Furthermore, the prognosis of patients who are managed by MDT is usually better. MDT has a great value in all presentation settings. The role of the pathologist in the team is of utmost importance, in particular with regards to information provided on Human Papilloma Virus (HPV) status, which has a well acknowledged independent prognostic value mainly in oropharyngeal carcinoma. In early stage disease, namely in T1-2 N0 M0 patients, the meetings within the MDT mainly involve surgeons and radiation therapists. Surgery represents the mainstay of treatment, while radiation therapy is a suitable alternative, in particular in patients with advanced age, poor performance status and comorbidities. In locally advanced disease, surgeons, medical oncologists and radiotherapists are the key people, since different approaches have been carried out. In operable patients, adjuvant chemoradiation is indicated when resection margins are involved or close, or in presence of extracapsular nodal spread. Concurrent chemoradiotherapy, preceeded or not by induction chemotherapy, is the favourite approach in this setting when surgery is strictly not indicated. In recurrent/metastatic disease chemotherapy and best supportive care are the main options, although local treatments, such as reirradiation and salvage surgery, are also worth considering. The standard chemotherapy treatment has finally evolved after about 30 years, and strong efforts are being pursued to further improve the outcome, mainly with the addition of new drugs.

Treatment of locally advanced non-small cell lung cancer (NSCLC) remains a significant challenge for oncologists, despite progress made in recent years in early diagnosis and therapy. This review focuses on integrated therapeutic approaches of patients with locally advanced NSCLC, summarizing the available evidence for patients with potentially resectable disease (stage IIIA-0/3) and with unresectable disease (stage IIIA-4/IIIB) and discussing several key questions related to the use of integrated approaches in NSCLC. Based on current evidence, neoadjuvant platinum-based combination chemotherapy is a treatment option in patients with potentially resectable stage IIIA-0/3: a 2-drug combination of platinum combined with a third-generation drug seems preferable, and at least 3 cycles of chemotherapy should be administered. There are no definitive evidences of clear superiority of surgery compared to radiotherapy for patients obtaining a response with neoadjuvant treatment: however, surgery is associated with a better local control, and subgroup analyses of randomized trials suggest improved outcome in patients in whom a complete resection could be obtained with a lobectomy, avoiding the increased surgical mortality associated with pneumonectomy. Standard treatment for patients with locally advanced, unresectable NSCLC is currently represented by combination of chemotherapy and radiotherapy. Concomitant approach has been proven superior to the sequential administration, although it is associated with higher risk of toxicity. All patients should be evaluated by a multidisciplinary team, skilled in multimodality treatment and should be counselled about risks and potential benefits of the different therapeutic approaches.

With optimized local treatment, achieved in the last years by TME surgery and the shift from a postoperative to a preoperative treatment approach, distant metastases have become the predominant mode of failure in rectal cancer. Therefore, the intensification of chemotherapy seems essential to improve distant control and survival in rectal cancer. The integration of newer generation chemotherapeutics and target agents into fluoropyrimidines-based chemoradiotherapy (CRT) has been the more actively pursued intensification strategy. However, early results from randomized phase III trials, evaluating the addition of oxaliplatin to preoperative fluoropyrimidines-based CRT, did not show a significant impact on early pathological response with the addition of oxaliplatin, with the exception of the German CAO/ARO/AIO-04 study. Moreover, the integration of target agents into preoperative CRT, although attractive in principle, has yielded low rates of pathologic complete responses when combined with cetuximab and some concerns on surgical morbidity following preoperative treatment with bevacizumab have been raised. Several novel strategies with different sequence of multimodal treatment components have been developed. However, the evidence that rectal cancers are a widely heterogeneous group of tumors with different prognostic implications, has indicated that the careful assessment of the risk of recurrence is a critical issue. In the era of the preoperative approach, staging with MRI, for its ability to predict the involvement of the mesorectal fascia, should be mandatory for all patients with rectal cancer, to refine the selection of patients for different treatment strategies. Moreover, considering that response to preoperative treatment is not uniformly obtained in all patients and post-operative chemotherapy is generally met with poor adherence, a risk-adapted strategy should be pursued in the postoperative setting as well. The selection of patients for different multidisciplinary treatment strategies based on clinico-pathological features, rather than the current “one size fits all” approach, will allow minimizing therapy and maximizing outcome for rectal cancer patients.

Endometrial cancer is a highly curable malignancy when it presents as uterine-confined disease, but the prognosis for metastatic or recurrent endometrial cancer is poor. For those patients which are diagnosed at an early stage, surgery alone may be adequate for cure and clinical outcome is often favorable, with approximately 80 % of cases surviving at 5 years. However, after primary diagnosis and treatment, roughly 20-30% of patients are expected to recur within the following 5 years. Adjuvant treatment for endometrial cancer is not yet clearly defined. FIGO Stage I-III endometrial cancer patients, usually undergo surgery and some of them are offered adjuvant treatment based on risk assessment. Grade, age, stage are considered all independent risk factors for recurrence. Radiotherapy (RT) has been considered the adjuvant treatment of choice for decades, being able to reduce local recurrence rate and improving progression free survival, but without any impact on overall survival. In the last two decades, a shift toward the use of systemic chemotherapy (CT) in addition or instead of radiation has occurred, although few prospective studies have been performed in this field.

The rapid approval of several novel agents has given prostate cancer patients and their treating physicians many new and effective therapeutic options. Four new medical therapies were recently approved on the basis of prolonged overall survival in castrationresistant prostate cancer (CRPC) patients: sipuleucel-T, cabazitaxel, abiraterone acetate and MDV3100. Additionally, there are several other promising prostate cancer agents in late-stage development, including PROSTVAC-VF, orteronel and radium-223 chloride, each with a novel mechanism of action. The treatment paradigm for these patients is rapidly evolving, with future study needed to define the optimal sequencing and potential combinations of these new agents. In this review, we discuss the recent progress in understanding the biology of this disease and examining the development of a variety of new agents with promising activity and a favorable toxicity profile, that have been investigated in the setting of hormonal, cytotoxic, immune and targeted therapy. In this new therapeutic setting of CRPC, clinicians will have an opportunity to balance benefits and harms of these new agents in an individual context.

The incidence of melanoma is rapidly increasing worldwide and the prognosis of patients with metastatic disease is still poor, with a median survival of 8–9 months and a 3-year overall survival (OS) rate less than 15% [1,2]. A complete surgical excision is the main treatment for primary cutaneous melanoma [3], but controversies about the extension of excision margins still remain [4]. Sentinel lymph node biopsy (SLNB) provides important prognostic and staging data by the identification of regional node-negative patients who would not benefit from a complete nodal dissection. However, there is no consensus in the definition of melanoma thickness to enforce the execution of the SLNB [5]. To date, Interferon-α (IFN-α)is the only approved adjuvant treatment after surgical excision of high-risk melanoma, but its indication remains still controversial [2,6].

The potential value of sugar-borate esters (SBEs) in the chemo-preventive therapy of prostate cancer has been reviewed. We propose that SBEs act as boron (B) vehicles, increasing the concentration of borate inside cancer cells relative to normal cells. Increased intracellular concentration of borate activates borate transporters, but also leads to growth inhibition and apoptosis. The effects of SBEs on normal cells are less dramatic because SBEs are naturally-occurring biochemicals, common and abundant in some fruits and vegetables, and also because borate dissociated from SBEs in natural diet doses is easily exported from normal cells. Cancer cell lines that over-express sugar transporters or under-express borate export are potential targets for SBE-based therapy. With regard to efficiency against cancer cells and drug preparation requirements, trigonal cis-diol boric monoesters will be one of the most effective class of SBEs. Because negative correlation exists between borate intake and the incidence of prostate cancer, and because most cancer cells overexpress sugar transporters, SBEs are proposed as a potential chemopreventive avenue in the fight against primary and recurrent prostate cancer.

Cancer has long been an area of extensive research both at the molecular as well as pharmaceutical level. However, lack of understanding of the underlying molecular signalling and the probable targets of therapeutics is a major concern in successful treatment of cancer. The situation becomes even worse, with the increasing side effects of the existing synthetic commercial drugs. Natural compounds especially those derived from plants have been best explored for their anticancer properties and most of them have been efficient against the known molecular targets of cancer. However, advent of biotechnology and resulting advances in medical arena have let to the increasing knowledge of newer carcinogenic signaling agents which has made the anticancer drug discovery even more demanding. The present review aims to bring forward the molecular mediators of cancer and compiles the plant derived anticancer agents with special emphasis on their clinical status. Since marine arena has proved to be a tremendous source of pharmaceutical agents, this review also focuses on the anticancer potential of marine plants especially algae. This is a comprehensive review covering major aspects of cancer mediation and utilization of marine flora for remediation of this deadly disease

Metastasis is the major cause of death in breast cancer patients. In this study, we investigated the effects of baicalin, a natural compound, on cell migration, invasion and metastasis using human breast cancer MDA-MB-231 cell line as model system. Baicalin not only dose-dependently inhibited MDA-MB-231 cells migration and in vitro invasion, but also suppressed the tumor outgrowth and the pulmonary metastasis of MDA-MB-231 cells in xenograft model. Importantly, treatment of baicalin caused little change in body weight, liver and kidney function of recipient animals. Tumorigenesis-inhibitory effect is likely linked to the capability of baicalin to downregulate metalloproteinase (MMP)-2, MMP-9, urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR) expression in MDA-MB-231 cells. As baicalin blocked p38 mitogen-activated protein kinase (MAPK) activity and treatment of p38MAPK inhibitor SB203580 led to the reduction of MMP-2, MMP-9, uPA and uPAR expressions, we concluded that baicalin suppresses the tumorigenecity of MDA-MB-231 cells by down-regulating MMP-2, MMP-9, uPA and uPAR expressions through the interruption of p38MAPK signaling pathway.

The structural changes in DNA caused by the combined effects of TiO2 nanoparticles (TiO2 NPs) and doxorubicin (DOX) were investigated along with their corresponding inhibitory roles in the growth of T47D and MCF7 cells. The UV-visible titration studies showed that DOX+ TiO2 NPs could form a novel complex with DNA. The data also reveal that the TiO2–DOX complex forms through a 1:4 stoichiometric ratio in solution. The values of binding constants reveal that DOX+TiO2 NPs interact more strongly with DNA as compared to TiO2 NPs or DOX alone. CD data show that DOX+TiO2 NPs can noticeably cause disturbance on DNA structure compared to TiO2 NPs or DOX alone, considering that DNA is relatively thermally stable in the condition used. The anticancer property of 0.3 µM DOX+ 60 µM TiO2 NPs and 0.4 µ M DOX+ 670 µM TiO2 NPs by MTT assay and DAPI stain demonstrates that this combination can tremendously diminish proliferation of T47D and MCF7cells compared to DOX or TiO2 NPs alone. The UV–Vis absorption spectroscopy, flow cytometry and fluorescence microscopy experiments show much more enhancement of DOX uptake through the use of TiO2 NPs. These results reveal that DOX+TiO2 NPs could proffer a novel strategy for the development of promising and efficient chemotherapy agents.

Objective: To investigate the effect of cucurmosin (CUS) on proliferation inhibition in the human pancreatic cancer cell line SW-1990 in vitro and in vivo. Methods: 1. MTT assay was used to analyse the proliferation inhibition of CUS in SW-1990 cells compared with gemcitabine (GEM) in vitro. 2. We established an NOD-SCID mice orthotopic transplantation model and estimated the proliferation inhibition effect of CUS in SW-1990 cells in vivo. 3. Western blot was used to determine the protein expressions of Caspase 3, Bcl-2, Caspase 9, PI3K, Akt, mTOR, P70S6k, and 4E-BP1 after CUS intervention. Results: 1. CUS inhibited the proliferation of pancreatic cancer cells and induced apoptosis in CUS dose- and time-dependent manners. 2. NOD-SCID mice models were established successfully, and the tumour proliferation inhibition rates of these models increased compared with the control group. 3. CUS inhibited all of the examined proteins in the PI3K/Akt/mTOR signalling pathway and induced active fragments of Caspase 3 and Caspase 9. Conclusion: 1. CUS can inhibit the growth of SW-1990 cells in vitro and in vivo. 2. CUS can induce apoptosis in SW-1990 cells to inhibit cell growth.

The ring A and D substituted analogs of pentacyclic triterpenoid Lantadene A (1) and B (2) were synthesized and evaluated for in vitro anticancer activity against four human cancer cell lines (HL-60, MCF-7, A549 and HCT-116). Analogs 3, 4, 7 and 8 showed enhanced inhibitory activity as compared with 1 and 2. These analogs were found more active than standard drug cisplatin with selective toxicity towards cancer cells and were inactive against normal cells (VERO). Furthermore, the mechanistic studies to investigate the effects of the new compounds on Akt protein in lung cancer cell line A549 and the NF-κB signalling pathway suggested that the compounds may exert their inhibitory activity on cancer cells through inhibition of both Akt and NF-κB activation. The docking studies of most potent analog (7) with 3D crystal structure of the nuclear factor kappa-B (NF-κB) P50 homodimer (PDB ID: 1NFK) revealed that carbonyl group of ester side chain and C-28 carboxylic acid groups were mainly involved in hydrogen bonding interaction. The oleanane frameworks was involved in strong hydrophobic interaction with amino acid phenylalanine and structure of lead compound have the potential to be developed as potent NF-κB inhibitor and anticancer agent.