The fight against cancer is not won in a single battle. Long after a cancer has
been beaten into remission, it can return. But oncologists are not sure exactly
why this happens, and the debate continues. New research led by Weizmann
Institute scientists in Rehovot shows that, at least for one type of blood
cancer, the source of cancer recurrence is a set of cells that do not
proliferate as quickly as regular cancer cells and thus are able to survive
chemotherapy. The findings, which appeared recently in the journal Blood, have
some important implications for the future of the war on cancer.
Cancer
involves a breakdown in the mechanism that regulates the pace of cell division.
When this happens, cells divide rapidly, leading to unchecked growth that
overruns the body. The most common chemotherapy drugs are those that
specifically attack cells undergoing rapid division, and these, indeed, often
destroy all the cancer and cure the patient.
But there are also quite a
few patients with this type of blood cancer who go through chemotherapy only to
have the cancer return. Several explanations have been proposed for why this
happens. One is that the chemotherapy does not kill every last cancer cell,
leaving a few to continue dividing out of control until the disease returns in
full force.
According to another explanation, chemotherapy does get all
the regular cancer cells, but there is another type of cancer cell that hides in
the body. As opposed to the rapidly dividing majority of cancer cells, these
undergo slow division, enabling them to evade the chemotherapy drugs. These
insidious cells can give rise to new rapidly-dividing cancer cells, which is why
they are known as “cancer stem cells.”
Which explanation is correct? The
debate is an important one because, if the first explanation holds true,
improving upon the existing treatments might help, while the second implies that
a completely different approach to treatment will be needed to root out the
slowly-dividing cancer stem cells.
To try to resolve the debate, the team
of Prof. Ehud Shapiro of the institute’s biological chemistry and applied
mathematics and computer sciences departments worked with scientists and
physicians from Rambam Medical Center and the Technion-Haifa Institute of
Technology in Haifa. They used a method of reconstructing cell lineage trees
that has been developed over the past few years in Shapiro’s lab. This method is
based on the fact that the genetic material in different body cells accumulates
unique mutations during cell division, and these mutations are passed on to
daughter cells.
By comparing mutations, they could map out cells’
detailed “family trees” and thus determine how far back they share a common
ancestor. The end product of this analysis is a tree that reconstructs the
genealogy of the cells from their earliest forebears at the base of the tree to
the youngest cells at the tips of the branches.
To reconstruct the cancer
cell lineage tree, the team used two sets of blood samples – the first taken
from leukemia patients right after the disease was diagnosed, and the second
from those patients who had undergone chemotherapy and in whom the cancer had
returned. The researchers could then trace the relationships of the recurring
cancer cells back to see if they descended from the original cancer
cells.
The lineage tree showed that, at least in some of the patients,
the source of the renewed cancer was not in the rapidly proliferating cancer
cells, but rather in cells that were close to the root of the tree. These cells
had only divided a few times.
In other words, the cancer arose from cells
that divide very slowly, making them resistant to the attacks of chemotherapy
drugs.
Shapiro explained: “We know that in many cases, chemotherapy alone
is not able to cure leukemia. Our results suggest that to completely eliminate
it, we must look for a treatment that will not only eliminate the rapidly
dividing cells, but also target the cancer stem cells that are resistant to
conventional treatment.”
The Knesset Finance Committee
has committed itself to the financing of a national program for reducing the
number of suicides, which began this year as a pilot project. This was announced
by committee chairman MK Moshe Gafni (United Torah Judaism) in a special session
on suicide prevention.
The discussion was initiated by MK Avraham
Michaeli of Shas who has in the past promoted several initiatives against
suicide in Israel. Michaeli said the pilot project has been very successful in
Ramle, Rehovot and Kafr Kana and was to wind down by the end of December because
it lacked NIS 600,000.
The pilot managed to very significantly reduce the
number of suicides in the three locations. There wasn’t a single case of suicide
in Kafr Kana since the project began, he said. Six government ministries are
partners in the project, which should be expanded and not halted, said the
MK.
The project, which screens people for suicidal tendencies and treats
them before it is too late, is led by the Health Ministry. Now, a budgetary
problem has arisen, and its continued existence is threatened by the lack of NIS
8 million. The six ministries – which besides Health are Education, Welfare and
Social Services, Industry, Trade and Employment, Absorption and Pensioners –
have not committed themselves to finance a continuation, Michaeli
said.
The project was described in the session by Health Ministry
associate directorgeneral Dr. Boaz Lev, who said that staffers were specially
trained to identify potential suicides and treat them. Multidisciplinary teams
of family physicians, social workers, psychologists, mental health teams,
teachers and school counsellors are integrated into the project.
Gafni
demanded that the Finance Ministry’s budgets division allocate money to
implement the program and asked the six ministries involved to apply for
allocations.
If they are turned down, he said, they should update the
Finance Committee, which would make sure during discussions of the 2013 budget
that money be transferred from other uses.
Going
to a hotel is fun, but it isn’t always easy for the disabled to enjoy themselves
during a vacation. A Ben-Gurion University study about the problems people with
disabilities face during their hotel experience has been voted a “Highly
Commended Award Winner” at the Literati Network of Emerald Publishing House
Awards for Excellence 2012.
Prof. Yaniv Poria, Prof. Arie Reichel of the
university’s hotel and tourism management department and Yael Brandt, a business
administration graduate of the Guilford Glazer Faculty of Business and
Management published their study recently in the International Journal of
Contemporary Hospitality Management.
The study focuses on the challenges
arising from the interactions between wheelchair users, individuals using
crutches as well as blind people and the hotel environment. It also suggested
ways of overcome these challenges.
As this study aims to broadcast the
genuine voice of people with disabilities, a qualitative research approach was
adopted. The study included in-depth interviews with 45 participants; 20 used
wheelchairs, 10 were dependent on crutches and 15 were blind.
Interpreted
by the social model of disability rather than by medical diagnosis methods, the
results suggest that the challenges the disabled confronted come from the
physical design of the environment as well as the behavior of the hotel staff.
The findings indicate that participants assigned more importance to staff
attitudes than to the physical environment.
The paper suggests to hotel
managers specific physical as well as interpersonal means to alleviate apparent
difficulties faced by people with disabilities in their hotel experiences. For
example, it was found that hotel employees treat people with disabilities as if
they were intellectually inferior by responding to their companion rather than
directly to them. These findings, BGU says, are of great importance to the
Israeli hospitality industry that is facing accessibility requirements by law.