Association of XRCC3 Polymorphism with Cervical Cancer in Bangladesh

This thesis report, submitted for a Master of Pharmacy degree at Khulna University, investigates the association between the XRCC3 Thr241Met polymorphism and the risk of cervical cancer in the Bangladeshi population. The study included 124 cervical cancer patients and 150 healthy controls, genotyping the study population using PCR-RFLP analysis. The results indicated that both heterozygous (C/T) and combined heterozygous plus variant homozygous (C/T+T/T) genotypes were significantly associated with cervical cancer susceptibility. The study found that the T allele increased the risk of cervical cancer by 1.68 times compared to the C allele. The research concludes that XRCC3 241-T allele carriers represent an increased risk of cervical cancer development in Bangladeshi women. The introduction provides background information on cancer, different types of cancer, global cancer status, and current cancer states in Bangladesh, with a specific focus on cervical cancer, its risk factors, and its prevalence. The study's findings contribute to the understanding of genetic factors influencing cervical cancer risk within the Bangladeshi population.

Association of Single Nucleotide Polymorphism with DNA Repair
Genes in Cervical Cancer among Bangladeshi Population
A THESIS REPORT
Submitted for the degree of
Master of Pharmacy (M. Pharm.)
Submitted By
Examination Roll No.: MS-181126
Examination Session: 2017-2018
Pharmacy Discipline
Life Science School, Khulna University
Khulna – 9208
DECEMBER, 2020

Dedicated
To
My Beloved Parents
&
My Respected Supervisor

DECLARATION
This is to certify that the thesis work entitled “Association of single nucleotide
polymorphism with DNA repair genes in cervical cancer among Bangladeshi
population” has been carried out by Laboni Das, examination roll no. MS-181126, session
2017-2018 in the Pharmacy Discipline, Khulna University, Khulna, Bangladesh. The above
thesis work or any part of this work has not been submitted in anywhere for the award of any
degree or diploma.
Signature of Candidate Signature of Supervisor
Laboni Das Professor Dr. Md. Mustafizur Rahman

APPROVAL
This is to certify that the thesis work submitted by Laboni Das entitled ―Association of
single nucleotide polymorphism with DNA repair genes in cervical cancer among
Bangladeshi population” has been approved by the Examination Committee for the partial
fulfillment of the requirements for the degree of Master of Pharmacy (M. Pharm) in the
Pharmacy Discipline, Khulna University, Khulna, Bangladesh in December, 2020.
Board of Examiner (or Examination Committee)
1. ………………………………… Chairman of the Committee
Name :
Designation :
University :
2. ………………………………… Member
Name :
Designation :
University :
3. ………………………………… Member
Name :
Designation :
University :
4. ………………………………… Member
Name :
Designation :
University :

ACKNOWLEDGEMENT
First of all, all praises be to the Almighty God, who enabled me to undertake & complete this
thesis work & finally write up the outcome. Individual efforts alone can never contribute in
totality to a successful completion of any venture. I would be failing in my duty if I did not
state my gratitude & appreciate to the following individuals who have made the valuable
contribution toward the thesis work.
I would like to express my deep gratitude & warm regards to my guide & thesis supervisor,
Dr. Md. Mustafizur Rahman, Professor, Pharmacy Discipline, Khulna University, for his
inspiration, constant guidance, valuable suggestions, sympathetic advice, and encouragement
during the course of study.
I would also like to convey my gratitude to my respected teacher and co-supervisor, Prof. Dr.
Samir Kumar Sadhu, Professor, Pharmacy Discipline, Khulna University, whose knowledge
and assistance helped this work to be successful.
I also wish to express my deepest gratitude to Dr. Ashis Kumar Das, Professor & Head,
Pharmacy Discipline, and all other respected teachers of Pharmacy Discipline for their noble
assistance, valuable guidance and inspiration.
My cordial thanks and gratitude to Robiul Islam, Asst. Register of lab, & Md. Ashikul Islam,
Lab. Assistant, Pharmacy Discipline, Khulna University for their kind and friendly
cooperation.
I also extend my gratitude to to all of my classmates and friends for their friendly co-
operations and occasional help. Last but not the least I am grateful to the authorities of the
Khulna University, for extending full laboratory facilities.
December, 2020 The Author

ABSTRACT
Background: Cervical cancer is the fourth most frequently diagnosed female malignancy as
well as the fourth leading cause of death in women worldwide. X-Ray Repair Cross
Complementing-3(XRCC3), a DNA repair gene plays an important role in maintaining
chromosomal stability and repairing DNA damage caused by exposures to radiation and
DNA cross-linking. This study was performed to investigate the relationship between XRCC3
Thr241Met polymorphism and cervical cancer risk in Bangladeshi females.
Method: The study included 124 cervical cancer patients and 150 healthy controls.
Genotyping of the study population was carried out by polymerase chain reaction-restriction
fragment length polymorphism (PCR–RFLP) analysis.
Results: Our study revealed that both heterozygous (C/T) and combined heterozygous plus
variant homozygous (C/T+T/T) genotypes were significantly associated with cervical cancer
susceptibility (OR =1.74, 95% CI = 1.02 to 2.94, p=0.0408 and OR =1.799, 95% CI = 1.07 to
3.01, p= 0.0259, respectively). Here C/T genotypes showed 1.74 times and combined
C/T+T/T genotypes showed 1.80 times higher risk of developing cervical cancer in our
population compared to normal homozygous C/C genotypes. However, mutant homozygous
T/T genotypes did not show statistically significant association with cervical cancer risk.
Comparing the allelic distribution we found that frequency of ‗C‘ and ‗T‘ alleles in cervical
cancer cases were found to be 79.43 and 20.56%, respectively, whereas in healthy controls
that were 86.66 and 13.33%, respectively. T allele increased the risk of cervical cancer
susceptibility by 1.68 times compared to C allele in Bangladeshi females (OR =1.68, 95% CI
= 1.06 to 2.64, p=0.0245).
Conclusion: Our study suggests that XRCC3 241-T allele carrier (C/T+T/T) represents an
increased risk of cervical cancer development in Bangladeshi women.

Chapter one
Introduction

1. Introduction
The thousands of years history of human civilization is the history of abundant development
in science and technology. With that continuity medical science has seen dramatic
development in last couple of centuries. Besides discovering successful treatments of
commonly known old diseases our researchers have also been discovering the right ways of
dealing with newly originated challenging diseases. But despite of the vast success,
researchers are still working tirelessly to discover the successful remedy for some old but
strong diseases. One of these stubborn lethal diseases is cancer.
1.1 Cancer
Cancer is a disease that sffeffa the body's cells. Cancer is known as a group of disease
complications which are commonly characterized by the uncontrolled growth and
proliferation of cells, resulting in death. One defining feature of cancer is the rapid creation of
abnormal cells which grow beyond their usual boundaries, and which can invade adjoining
parts of the body and spread to other organs. Cancer can start any place in the body. It starts
when cells grow out of control and crowd out normal cells. This makes it hard for the body to
work the way it should. It is indeed a pandemic burden affecting people of all ages, races,
incomes, and statuses; principally by commencing a state of sustaining proliferative
signaling, avoiding the growth suppressors, protecting the defective cell death, accelerating
the replicative immortality, inducing angiogenesis, and finally by activating invasion and
metastasis [Torre et al 2012].
Cancer is also characterized by acquisition of metastatic properties. In most cases, activation
of oncogenes and deactivation of tumor suppressor genes lead to uncontrolled cell cycle
progression and inactivation of apoptotic mechanisms [Vogelstein et al 2004]. rsnfeC

Cepresents an altered genome that contains a unique and unpredictable number of point
mutations, translocations, fusions, and other aberrations.
Human cells form new cells as our body needs them, by growing and dividing. When cells
grow old or become damaged, they die, and new cells take their place. When cancer
develops, this orderly process breaks down. As cells become more and more abnormal, old or
damaged cells survive when they should die, and new cells form when they are not needed.
These extra cells can divide without stopping and may form growths called tumors. [NIH-
National Cancer Institute]
1.2 Different Types of Cancer
There are over 200 types of cancer. However, the NCI lists several general categories. Here is
a list of some specific types of cancer-
Figure 1.1: Start and spreading of cancer

 Carcinoma: When cancer begins in skin or tissues lining or covering internal organs
are called carcinoma. For example- Lung, skin, pancreatic, colon, ovarian cancer,
epithelial, squamous, basal cell carcinomas, melanoma, adenoma, papilloma.
 Sarcoma: When cancer begins in bone, cartilage, muscle, fat, blood vessels or other
connective tissues is called sarcoma. For example- bone cancer, soft tissue cancer,
osteosarcoma, synovial sarcoma, angiosarcoma, liposarcoma, rhabdosarcoma,
fibrosarcoma.
 Leukemia: Cancer starting in blood forming tissue like the bone marrow and then
large number of abnormal blood cells are produced and enter the blood is called
leukemia. For example-limphoblastic leukemia, T cell leukemia, hairy cell leukemia,
myelogenous leukemia.
 Lymphoma and myeloma: Cancers that begin in the cells of the immune system --
"lymphoma," T-cell lymphomas, B-cell lymphomas, Hodgkin lymphomas, non-
Hodgkin lymphoma, and lymphoproliferative lymphomas
 Central nervous system cancers: Cancers that begin in the tissues of the brain and
spinal cord -- "brain and spinal cord tumors," gliomas, meningiomas, pituitary
adenomas, vestibular schwannomas, primary CNS lymphomas, and primitive
neuroectodermal tumors
Not included in the above types listed are metastatic cancers; this is because metastatic cancer
cells usually arise from a cell type listed above and the major difference from the above types
is ;that these cells are now present in a tissue from which the cancer cells did not originally
develop. Consequently, if the terms "metastatic cancer" is used, for accuracy, the tissue from
which the cancer cells arose should be included.

1.3 Global Cancer Status
A press release by International Agency for Research on Cancer (IARC) in (N 263) on 12
September 2018 stated that Cancer burden rises to 18.1 million new cases and 9.6 million
cancer deaths in 2018. An article published in the same day in CA: A Cancer Journal for
Clinicians highlighted that the large geographical diversity in cancer occurrence and the
variations in the magnitude and profile of the disease between and within world regions.
The global cancer burden was estimated to rise to 18.1 million new cases and 9.6 million
deaths in 2018. The most alarming matter is one in 5 men and one in 6 women worldwide
develop cancer during their lifetime, and one in 8 men and one in 11 women die from the
disease [Ferlay et al. 2018]. The total number of people who are alive within 5 years of a
cancer diagnosis is called the 5-year prevalence. This 5-year prevalence, worldwide, is
estimated to be 43.8 million [https://www.who.int/cancer/PRGlobocanFinal.pdf].
Cancer status of 2019
Cancer site Cases Deaths
Lung 2,093,876 (11.6) 1,761,007 (18.4)
Breast 2,088,849 (11.6) 626,679 (6.6)
Prostate 1,276,106 (7.1) 358,989 (3.8)
Colon 1,096,601 (6.1) 551,269 (5.8)
Nonmelanoma of skin 1,042,056 (5.8) 65,155 (0.7)
Stomach 1,033,701 (5.7) 782,685 (8.2)
Liver 841,080 (4.7) 781,631 (8.2)
Rectum 704,376 (3.9) 310,394 (3.2)
Esophagus 572,034 (3.2) 508,585 (5.3)

Cervix uteri 569,847 (3.2) 311,365 (3.3)
Thyroid 567,233 (3.1) 41,071 (0.4)
Bladder 549,393 (3.0) 199,922 (2.1)
Non‐Hodgkin lymphoma 509,590 (2.8) 248,724 (2.6)
Pancreas 458,918 (2.5) 432,242 (4.5)
Leukemia 437,033 (2.4) 309,006 (3.2)
Kidney 403,262 (2.2) 175,098 (1.8)
Corpus uteri 382,069 (2.1) 89,929 (0.9)
Lip, oral cavity 354,864 (2.0) 177,384 (1.9)
Brain, nervous system 296,851 (1.6) 241,037 (2.5)
Ovary 295,414 (1.6) 184,799 (1.9)
1.4 Current Cancer State in Bangladesh [GLOBOCAN 2018]