Natural products isolated from marine mollusks and sponges can reverse multidrug resistance in cancer cells

Oceans are a treasure trove of naturally produced chemical compounds with impressive and varied biological activity. One class of these compounds, the lamellarins, has some members that are cytotoxic, while others are able to reverse multidrug resistance in certain cancer cells. These lamellarins (see below structure) act by inhibiting the so-called P-glycoprotein, which enhances transport of anticancer agents out of cancer cells, thus rendering the cells multidrug resistant.

Now researchers lead by Professor Rob Capon, have set out to determine the structures of a variety of lamellarins and correlate them to the activity of the compounds. As they report in Chemistry—An Asian Journal, the activity is not determined by the core structure of the compounds but rather depends on the exact nature of pendant groups adorning the periphery of the molecule. Those compounds in which many hydroxy (OH) groups had been replaced with methoxy (OCH₃) were able to reverse multidrug resistance in human colon cancer cells, while those featuring a large number of hydroxy groups showed higher cytotoxic activity.

Natural products such as the lamellarins are often valued for their cytotoxic properties for use as anticancer drugs. Capon, however, comments, "Our investigation reaffirms the view that non-cytotoxic natural products can exhibit valuable biological properties that allude to both an ecological advantage and a pharmacological potential....

Ref : http://onlinelibrary.wiley.com/doi/10.1002/asia.201101049/abstract;jsessionid=D96AD6C21A9E2EAF7D966C0743768A2A.d01t03

More Evidence for Oxaliplatin as Colon Cancer Chemotherapy

In continuation of my update on Oxaliplatin 

Adding oxaliplatin to a standard chemotherapy regimen boosts survival rates for patients with advanced colon cancer, according to a new study that bolsters previous research on the drug by looking at a broader group of patients.

In past studies, oxaliplatin, as an adjuvant to the established treatment of 5-fluorouracil (5-FU), improved survival by up to 23 percent. But the new study looked at a different group of colon cancer patients, who were older, sicker, more racially diverse and had never participated in a controlled clinical study.

To determine whether oxaliplatin would show a similar benefit among a "real-world" population of patients, the authors sifted through five cancer registries containing survival information on more than 4,000 people with stage 3 colon cancer. All were younger than 75, and all had begun chemotherapy -- either a standard regimen or in combination with oxaliplatin -- within four months of having surgery between 2004 and 2009.

Researchers lead by Dr.Hanna K. Sanoff compared their survival rates with those of nearly 8,300 patients who had participated in one of five different clinical trials using oxaliplatin.

The addition of oxaliplatin to standard chemotherapy protocols was found to be just as effective in prolonging survival among the community-based set of patients - including the elderly, minorities and those with additional complicating health issues  who were not enrolled in studies.

More....